1
|
Ercetin A, Aslantaş K, Özgün Ö, Perçin M, Chandrashekarappa MPG. Optimization of Machining Parameters to Minimize Cutting Forces and Surface Roughness in Micro-Milling of Mg13Sn Alloy. Micromachines (Basel) 2023; 14:1590. [PMID: 37630126 PMCID: PMC10456406 DOI: 10.3390/mi14081590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/02/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023]
Abstract
This comprehensive study investigates the micro-milling of a Mg13Sn alloy, a material of considerable interest in various high-precision applications, such as biomedical implants. The main objective of the study was to explore the optimizations of variable feed per tooth (fz), cutting speed (Vc), and depth of cut (ap) parameters on the key outcomes of the micro-milling process. A unique experimental setup was employed, employing a spindle capable of achieving up to 60,000 revolutions per minute. Additionally, the study leveraged linear slides backed by micro-step motors to facilitate precise axis movements, thereby maintaining a resolution accuracy of 0.1 μm. Cutting forces were accurately captured by a mini dynamometer and subsequently evaluated based on the peak to valley values for Fx (tangential force) and Fy (feed force). The study results revealed a clear and complex interplay between the varied cutting parameters and their subsequent impacts on the cutting forces and surface roughness. An increase in feed rate and depth of cut significantly increased the cutting forces. However, the cutting forces were found to decrease noticeably with the elevation of cutting speed. Intriguingly, the tangential force (Fx) was consistently higher than the feed force (Fy). Simultaneously, the study determined that the surface roughness, denoted by Sa values, increased in direct proportion to the feed rate. It was also found that the Sa surface roughness values decreased with the increase in cutting speed. This study recommends a parameter combination of fz = 5 µm/tooth feed rate, Vc = 62.8 m/min cutting speed, and ap = 400 µm depth of cut to maintain a Sa surface roughness value of less than 1 µm while ensuring an optimal material removal rate and machining time. The results derived from this study offer vital insights into the micro-milling of Mg13Sn alloys and contribute to the current body of knowledge on the topic.
Collapse
Affiliation(s)
- Ali Ercetin
- Department of Naval Architecture and Marine Engineering, Maritime Faculty, Bandırma Onyedi Eylul University, Bandırma 10200, Turkey
| | - Kubilay Aslantaş
- Department of Mechanical Engineering, Faculty of Technology, Afyon Kocatepe University, Afyonkarahisar 03200, Turkey;
| | - Özgür Özgün
- Department of Occupational Health and Safety, Faculty of Health Sciences, Bingöl University, Bingöl 12000, Turkey;
| | - Mustafa Perçin
- Department of Machine and Metal Technologies, Vocational School of Technical Sciences, Bursa Uludag University, Bursa 16059, Turkey;
| | | |
Collapse
|
2
|
Shang P, Zhang H, Liu X, Yang Z, Liu B, Liu T. Cutting-Force Modeling Study on Vibration-Assisted Micro-Milling of Bone Materials. Micromachines (Basel) 2023; 14:1422. [PMID: 37512733 PMCID: PMC10384012 DOI: 10.3390/mi14071422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023]
Abstract
This study aims to enhance surgical safety and facilitate patient recovery through the investigation of vibration-assisted micro-milling technology for bone-material removal. The primary objective is to reduce cutting force and improve surface quality. Initially, a predictive model is developed to estimate the cutting force during two-dimensional (2D) vibration-assisted micro-milling of bone material. This model takes into account the anisotropic structural characteristics of bone material and the kinematics of the milling tool. Subsequently, an experimental platform is established to validate the accuracy of the cutting-force model for bone material. Micro-milling experiments are conducted on bone materials, with variations in cutting direction, amplitude, and frequency, to assess their impact on cutting force. The experimental results demonstrate that selecting appropriate machining parameters can effectively minimize cutting force in 2D vibration-assisted micro-milling of bone materials. The insights gained from this study provide valuable guidance for determining cutting parameters in vibration-assisted micro-milling of bone materials.
Collapse
Affiliation(s)
- Peng Shang
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| | - Huaiqing Zhang
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| | - Xiaopeng Liu
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| | - Zhuang Yang
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| | - Bingfeng Liu
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| | - Teng Liu
- School of Mechanical Engineering, Hebei University of Technology, Tianjin 300400, China
| |
Collapse
|
3
|
Karakılınç U, Ergene B, Yalçın B, Aslantaş K, Erçetin A. Comparative Analysis of Minimum Chip Thickness, Surface Quality and Burr Formation in Micro-Milling of Wrought and Selective Laser Melted Ti64. Micromachines (Basel) 2023; 14:1160. [PMID: 37374745 DOI: 10.3390/mi14061160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 05/27/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023]
Abstract
Selective laser melting (SLM) is a three-dimensional (3D) printing process that can manufacture functional parts with complex geometries as an alternative to using traditional processes, such as machining wrought metal. If precision and a high surface finish are required, particularly for creating miniature channels or geometries smaller than 1 mm, the fabricated parts can be further machined. Therefore, micro milling plays a significant role in the production of such miniscule geometries. This experimental study compares the micro machinability of Ti-6Al-4V (Ti64) parts produced via SLM compared with wrought Ti64. The aim is to investigate the effect of micro milling parameters on the resulting cutting forces (Fx, Fy, and Fz), surface roughness (Ra and Rz), and burr width. In the study, a wide range of feed rates was considered to determine the minimum chip thickness. Additionally, the effects of the depth of cut and spindle speed were observed by taking into account four different parameters. The manufacturing method for the Ti64 alloy does not affect the minimum chip thickness (MCT) and the MCT for both the SLM and wrought is 1 μm/tooth. SLM parts exhibit acicular α martensitic grains, which result in higher hardness and tensile strength. This phenomenon prolongs the transition zone of micro-milling for the formation of minimum chip thickness. Additionally, the average cutting force values for SLM and wrought Ti64 fluctuated between 0.072 N and 1.96 N, depending on the micro milling parameters used. Finally, it is worth noting that micro-milled SLM workpieces exhibit lower areal surface roughness than wrought ones.
Collapse
Affiliation(s)
- Uçan Karakılınç
- Department of Computer Programming, Isparta University of Applied Sciences, 32200 Isparta, Turkey
| | - Berkay Ergene
- Department of Mechanical Engineering, Pamukkale University, 20160 Denizli, Turkey
| | - Bekir Yalçın
- Department of Mechanical Engineering, Afyon Kocatepe University, 03200 Afyonkarahisar, Turkey
| | - Kubilay Aslantaş
- Department of Mechanical Engineering, Afyon Kocatepe University, 03200 Afyonkarahisar, Turkey
| | - Ali Erçetin
- Department of Naval Architecture and Marine Engineering, Faculty of Maritime, Bandırma Onyedi Eylul University, 10200 Bandırma, Turkey
| |
Collapse
|
4
|
Van Hileghem L, Kushwaha S, Piovesan A, Verboven P, Nicolaï B, Reynaerts D, Dal Dosso F, Lammertyn J. Innovative Fabrication of Hollow Microneedle Arrays Enabling Blood Sampling with a Self-Powered Microfluidic Patch. Micromachines (Basel) 2023; 14:615. [PMID: 36985022 PMCID: PMC10052199 DOI: 10.3390/mi14030615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/28/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
Microneedles are gaining a lot of attention in the context of sampling cutaneous biofluids such as capillary blood. Their minimal invasiveness and user-friendliness make them a prominent substitute for venous puncture or finger-pricking. Although the latter is suitable for self-sampling, the impracticality of manual handling and the difficulty of obtaining enough qualitative sample is driving the search for better solutions. In this context, hollow microneedle arrays (HMNAs) are particularly interesting for completely integrating sample-to-answer solutions as they create a duct between the skin and the sampling device. However, the fabrication of sharp-tipped HMNAs with a high aspect ratio (AR) is challenging, especially since a length of ≥1500 μm is desired to reach the blood capillaries. In this paper, we first described a novel two-step fabrication protocol for HMNAs in stainless steel by percussion laser drilling and subsequent micro-milling. The HMNAs were then integrated into a self-powered microfluidic sampling patch, containing a capillary pump which was optimized to generate negative pressure differences up to 40.9 ± 1.8 kPa. The sampling patch was validated in vitro, showing the feasibility of sampling 40 μL of liquid. It is anticipated that our proof-of-concept is a starting point for more sophisticated all-in-one biofluid sampling and point-of-care testing systems.
Collapse
Affiliation(s)
- Lorenz Van Hileghem
- Biosensors Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
- Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium
| | - Shashwat Kushwaha
- Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium
- Manufacturing Processes and Systems, Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
- Member of Flanders Make, 3000 Leuven, Belgium
| | - Agnese Piovesan
- Postharvest Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
| | - Pieter Verboven
- Postharvest Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
| | - Bart Nicolaï
- Postharvest Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
| | - Dominiek Reynaerts
- Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium
- Manufacturing Processes and Systems, Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
- Member of Flanders Make, 3000 Leuven, Belgium
| | - Francesco Dal Dosso
- Biosensors Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
- Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium
| | - Jeroen Lammertyn
- Biosensors Group, Department of Biosystems, KU Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
- Institute of Micro- and Nanoscale Integration, KU Leuven, 3001 Leuven, Belgium
| |
Collapse
|
5
|
Wittek CGR, Steinhoff L, Raumel S, Reißfelder M, Dencker F, Wurz MC. Process Development for Batch Production of Micro-Milling Tools Made of Silicon Carbide by Means of the Dry Etching Process. Micromachines (Basel) 2023; 14:580. [PMID: 36984985 PMCID: PMC10058442 DOI: 10.3390/mi14030580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/25/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Downsized and complex micro-machining structures have to meet quality requirements concerning geometry and convince through increasing functionality. The development and use of cutting tools in the sub-millimeter range can meet these demands and contribute to the production of intelligent components in biomedical technology, optics or electronics. This article addresses the development of double-edged micro-cutters, which consist of a two-part system of cutter head and shaft. The cutting diameters are between 50 and 200 μm. The silicon carbide cutting heads are manufactured from the solid material using microsystem technology. The substrate used can be structured uniformly via photolithography, which means that 5200 homogeneous micro-milling heads can be produced simultaneously. This novel batch approach represents a contrast to conventionally manufactured micro-milling cutters. The imprint is taken by means of reactive ion etching using a mask made of electroplated nickel. Within this dry etching process, characteristic values such as the etch rate and flank angle of the structures are critical and will be compared in a parameter analysis. At optimal parameters, an anisotropy factor of 0.8 and an etching rate of 0.34 µm/min of the silicon carbide are generated. Finally, the milling heads are diced and joined. In the final machining tests, the functionality is investigated and any signs of wear are evaluated. A tool life of 1500 mm in various materials could be achieved. This and the milling quality achieved are in the range of conventional micro-milling cutters, which gives a positive outlook for further development.
Collapse
Affiliation(s)
- Christian-G. R. Wittek
- Institute of Micro Production Technology (IMPT), Leibniz University Hanover, 30823 Garbsen, Germany
| | - Lukas Steinhoff
- Institute of Micro Production Technology (IMPT), Leibniz University Hanover, 30823 Garbsen, Germany
| | - Selina Raumel
- Institute of Micro Production Technology (IMPT), Leibniz University Hanover, 30823 Garbsen, Germany
| | | | - Folke Dencker
- Institute of Micro Production Technology (IMPT), Leibniz University Hanover, 30823 Garbsen, Germany
| | - Marc C. Wurz
- Institute of Micro Production Technology (IMPT), Leibniz University Hanover, 30823 Garbsen, Germany
| |
Collapse
|
6
|
Baig A, Jaffery SHI, Khan MA, Alruqi M. Statistical Analysis of Surface Roughness, Burr Formation and Tool Wear in High Speed Micro Milling of Inconel 600 Alloy under Cryogenic, Wet and Dry Conditions. Micromachines (Basel) 2022; 14:13. [PMID: 36677073 PMCID: PMC9865365 DOI: 10.3390/mi14010013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Super alloys offer excellent mechanical and chemical properties at elevated temperatures that make them an attractive choice for aerospace, automotive and chemical processing, and marine applications. These alloys are, however, difficult to machine due to their high strength at elevated temperatures, low thermal conductivity and work hardening. In this study, micro milling of Inconel 600 super alloy has been carried out and the effects of the key input parameters (cutting speed, feed rate, depth of cut) on response parameters (burr formation, surface roughness and tool wear), under various cooling conditions (dry, wet and cryogenic), have been analyzed. High speed micro milling (range up to 80,000 RPM) was carried out, while keeping the feed rate values below and above the cutting edge radius. The Taguchi design of experiments was used during this study. The results have been analyzed using SEM and 3D optical microscopy. Analysis of Variance (ANOVA) revealed that the best surface roughness values can be achieved under cryogenic machining condition with an overall contribution ratio of 28.69%. It was also revealed that cryogenic cooling resulted in the highest tool life with the contribution ratio of cooling conditions at 26.52%.
Collapse
Affiliation(s)
- Amjad Baig
- School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
| | - Syed Husain Imran Jaffery
- School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
| | - Muhammad Ali Khan
- School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
- Department of Mechanical Engineering, College of Electrical and Mechanical Engineering (CEME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
| | - Mansoor Alruqi
- Department of Mechanical Engineering, Shaqra University, Shaqra 11911, Saudi Arabia
| |
Collapse
|
7
|
Konopka J, Kołodziejek D, Flont M, Żuchowska A, Jastrzębska E, Brzózka Z. Exploring Endothelial Expansion on a Chip. Sensors (Basel) 2022; 22:9414. [PMID: 36502120 PMCID: PMC9741423 DOI: 10.3390/s22239414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/22/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Angiogenesis is the development of new blood vessels from the existing vasculature. Its malfunction leads to the development of cancers and cardiovascular diseases qualified by the WHO as a leading cause of death worldwide. A better understanding of mechanisms regulating physiological and pathological angiogenesis will potentially contribute to developing more effective treatments for those urgent issues. Therefore, the main goal of the following study was to design and manufacture an angiogenesis-on-a-chip microplatform, including cylindrical microvessels created by Viscous Finger Patterning (VFP) technique and seeded with HUVECs. While optimizing the VFP procedure, we have observed that lumen's diameter decreases with a diminution of the droplet's volume. The influence of Vascular Endothelial Growth Factor (VEGF) with a concentration of 5, 25, 50, and 100 ng/mL on the migration of HUVECs was assessed. VEGF's solution with concentrations varying from 5 to 50 ng/mL reveals high angiogenic potential. The spatial arrangement of cells and their morphology were visualized by fluorescence and confocal microscopy. Migration of HUVECs toward loaded angiogenic stimuli has been initiated after overnight incubation. This research is the basis for developing more complex vascularized multi-organ-on-a-chip microsystems that could potentially be used for drug screening.
Collapse
Affiliation(s)
- Joanna Konopka
- Faculty of Chemistry, Warsaw University of Technology, 00-661 Warszawa, Poland
| | - Dominik Kołodziejek
- Faculty of Chemistry, Warsaw University of Technology, 00-661 Warszawa, Poland
| | - Magdalena Flont
- Centre for Advanced Materials and Technologies CEZAMAT, Warsaw University of Technology, 02-822 Warszawa, Poland
| | - Agnieszka Żuchowska
- Faculty of Chemistry, Warsaw University of Technology, 00-661 Warszawa, Poland
| | - Elżbieta Jastrzębska
- Faculty of Chemistry, Warsaw University of Technology, 00-661 Warszawa, Poland
- Centre for Advanced Materials and Technologies CEZAMAT, Warsaw University of Technology, 02-822 Warszawa, Poland
| | - Zbigniew Brzózka
- Faculty of Chemistry, Warsaw University of Technology, 00-661 Warszawa, Poland
| |
Collapse
|
8
|
Bhoi S, Kumar A, Prasad A, Meena CS, Sarkar RB, Mahto B, Ghosh A. Performance Evaluation of Different Coating Materials in Delamination for Micro-Milling Applications on High-Speed Steel Substrate. Micromachines (Basel) 2022; 13:mi13081277. [PMID: 36014199 PMCID: PMC9415885 DOI: 10.3390/mi13081277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 05/17/2023]
Abstract
The objective of the present work is to carry out analytical and finite element analysis for commonly used coating materials for micro-milling applications on high-speed steel substrate and evaluate the effects of different parameters. Four different coating materials were selected for micro-milling applications: titanium nitride (TiN), diamond-like carbon (DLC), aluminium titanium nitride (AlTiN) and titanium silicon nitride (TiSiN). A 3D finite element model of coating and substrate assembly was developed in Abaqus to find the Hertzian normal stress when subjected to normal load of 4 N, applied with the help of a rigid ball. The radius of the rigid ball was 200 µm. For all the coating materials, the length was 3 mm, the width was 1 mm, and the thickness was 3 µm. For the high-speed steel substrate, the length was 3 mm, the width was 1 mm, and the thickness was 50 µm. Along the length and width, coating and substrate both were divided into 26 equal parts. The deformation behaviour of all the coating materials was considered as linear-elastic and that of the substrate was characterized as elastic-plastic. The maximum normal stress developed in the FEA model was 12,109 MPa. The variation of the FEA result from the analytical result (i.e., 12,435.97 MPa is 2.63%) which is acceptable. This confirms that the FEA model of coating-substrate assembly is acceptable. The results shows that the TiSiN coating shows least plastic equivalent strain in the substrate, which serves the purpose of protecting the substrate from plastic deformation and the TiSiN of 3 micron thickness is the most optimum coating thickness for micro-milling applications.
Collapse
Affiliation(s)
- Sandeep Bhoi
- Department of Mechanical Engineering, Parala Maharaja Engineering College, Berhampur 761003, Odisha, India
| | - Ashwani Kumar
- Technical Education Department Uttar Pradesh, Kanpur 208024, Uttar Pradesh, India
| | - Arbind Prasad
- Department of Mechanical Engineering, Katihar Engineering College (Under Department of Science & Technology, Government of Bihar), Katihar 854109, Bihar, India
| | - Chandan Swaroop Meena
- CSIR-Central Building Research Institute, Roorkee 247667, Uttarakhand, India
- Correspondence: (C.S.M.); (A.G.)
| | - Rudra Bubai Sarkar
- Research and Development Division, Tata Steel Ltd., Burma Mines, Jamshedpur 831007, Jharkhand, India
| | - Bidyanand Mahto
- Government Engineering College Vaishali (Under Department of Science & Technology, Government of Bihar), Vailshali 844115, Bihar, India
| | - Aritra Ghosh
- College of Engineering, Mathematics and Physical Sciences, Renewable Energy, University of Exeter, Penryn, Cornwall TR109FE, UK
- Correspondence: (C.S.M.); (A.G.)
| |
Collapse
|
9
|
Nguyen T, Ho L, Moinuddin SM, Sarkar T, Saha D, Ahsan F. Multicellular Cell Seeding on a Chip: New Design and Optimization towards Commercialization. Biosensors (Basel) 2022; 12:bios12080587. [PMID: 36004984 PMCID: PMC9405756 DOI: 10.3390/bios12080587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/13/2022] [Accepted: 07/29/2022] [Indexed: 05/09/2023]
Abstract
This paper shows both experimental and in-depth theoretical studies (including simulations and analytical solutions) on a microfluidic platform to optimize its design and use for 3D multicellular co-culture applications, e.g., creating a tissue-on-chip model for investigating diseases such as pulmonary arterial hypertension (PAH). A tissue microfluidic chip usually has more than two channels to seed cells and supply media. These channels are often separated by barriers made of micro-posts. The optimization for the structures of these micro-posts and their spacing distances is not considered previously, especially for the aspects of rapid and cost-efficient fabrication toward scaling up and commercialization. Our experimental and theoretical (COMSOL simulations and analytical solutions) results showed the followings: (i) The cell seeding was performed successfully for this platform when the pressure drops across the two posts were significantly larger than those across the channel width. The circular posts can be used in the position of hexagonal or other shapes. (ii) In this work, circular posts are fabricated and used for the first time. They offer an excellent barrier effect, i.e., prevent the liquid and gel from migrating from one channel to another. (iii) As for rapid and cost-efficient production, our computer-aided manufacturing (CAM) simulation confirms that circular-post fabrication is much easier and more rapid than hexagonal posts when utilizing micro-machining techniques, e.g., micro-milling for creating the master mold, i.e., the shim for polymer injection molding. The findings open up a possibility for rapid, cost-efficient, large-scale fabrication of the tissue chips using micro-milling instead of expensive clean-room (soft) lithography techniques, hence enhancing the production of biochips via thermoplastic polymer injection molding and realizing commercialization.
Collapse
Affiliation(s)
- Trieu Nguyen
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, California Northstate University, Elk Grove, CA 95757, USA; (T.N.); (L.H.); (S.M.M.); (T.S.)
- East Bay Institute for Research & Education (EBIRE), Mather, CA 95655, USA;
| | - Linh Ho
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, California Northstate University, Elk Grove, CA 95757, USA; (T.N.); (L.H.); (S.M.M.); (T.S.)
| | - Sakib M. Moinuddin
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, California Northstate University, Elk Grove, CA 95757, USA; (T.N.); (L.H.); (S.M.M.); (T.S.)
- East Bay Institute for Research & Education (EBIRE), Mather, CA 95655, USA;
| | - Tanoy Sarkar
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, California Northstate University, Elk Grove, CA 95757, USA; (T.N.); (L.H.); (S.M.M.); (T.S.)
| | - Dipongkor Saha
- East Bay Institute for Research & Education (EBIRE), Mather, CA 95655, USA;
| | - Fakhrul Ahsan
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, California Northstate University, Elk Grove, CA 95757, USA; (T.N.); (L.H.); (S.M.M.); (T.S.)
- East Bay Institute for Research & Education (EBIRE), Mather, CA 95655, USA;
- MedLuidics, Elk Grove, CA 95757, USA
- Correspondence:
| |
Collapse
|
10
|
Liu T, Wang Q, Wang W. Micro-Milling Tool Wear Monitoring via Nonlinear Cutting Force Model. Micromachines (Basel) 2022; 13:943. [PMID: 35744558 DOI: 10.3390/mi13060943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/06/2022] [Accepted: 06/10/2022] [Indexed: 11/18/2022]
Abstract
Mechanistic cutting force model has the potential for monitoring micro-milling tool wear. However, the existing studies mainly consider the linear cutting force model, and they are incompetent to monitor the micro-milling tool wear which has a significant nonlinear effect on the cutting force due to the cutting-edge radius size effect. In this study, a nonlinear mechanistic cutting force model considering the comprehensive effect of cutting-edge radius and tool wear on the micro-milling force is constructed for micro-milling tool wear monitoring. A stepwise offline optimization approach is proposed to estimate the multiple parameters of the model. By minimizing the gap between the theoretical force expressed by the nonlinear model and the force measured in real-time, the tool wear condition is online monitored. Experiments show that, compared with the linear model, the nonlinear model has significantly improved cutting force prediction accuracy and tool wear monitoring accuracy.
Collapse
|
11
|
Sun Q, Zhou J, Li P. Simulations and Experiments on the Micro-Milling Process of a Thin-Walled Structure of Al6061-T6. Materials (Basel) 2022; 15:ma15103568. [PMID: 35629597 PMCID: PMC9145201 DOI: 10.3390/ma15103568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/05/2022] [Accepted: 05/13/2022] [Indexed: 02/05/2023]
Abstract
Aluminum alloy (Al6061-T6) is an alloy with strong corrosion resistance, excellent disassembly, and moderate strength, which is widely used in the fields of construction, automobile, shipping, and aerospace manufacturing. Researching on the influence of machining precision and surface quality on the micro-milling process of thin-walled structures of Al6061 is highly significant. Combined with the two simulations (DEFORM-3D simulation and interactive finite element numerical simulation (FEM)) and milling experimental verification, the deformations, errors, and surface quality of milling thin-walled Al6061 were analyzed. The simulations and experimental results show that the deformation of milling a micro thin-walled structure was caused by the vertical stiffness of the thin-walled structure and the cutting force. Surface micromorphology further characterized and showed a poorer quality area, top burr, and concave defects, which directly affect machining quality. It is necessary to improve the surface quality, reduce the surface defects, and increase the stiffness at the top of thin-walled structures in future work.
Collapse
|
12
|
Liu T, Zhang K, Wang G, Wang C. Prediction of Nonlinear Micro-Milling Force with a Novel Minimum Uncut Chip Thickness Model. Micromachines (Basel) 2021; 12:1495. [PMID: 34945345 DOI: 10.3390/mi12121495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/27/2021] [Accepted: 11/28/2021] [Indexed: 11/17/2022]
Abstract
The minimum uncut chip thickness (MUCT), dividing the cutting zone into the shear region and the ploughing region, has a strong nonlinear effect on the cutting force of micro-milling. Determining the MUCT value is fundamental in order to predict the micro-milling force. In this study, based on the assumption that the normal shear force and the normal ploughing force are equivalent at the MUCT point, a novel analytical MUCT model considering the comprehensive effect of shear stress, friction angle, ploughing coefficient and cutting-edge radius is constructed to determine the MUCT. Nonlinear piecewise cutting force coefficient functions with the novel MUCT as the break point are constructed to represent the distribution of the shear/ploughing force under the effect of the minimum uncut chip thickness. By integrating the cutting force coefficient function, the nonlinear micro-milling force is predicted. Theoretical analysis shows that the nonlinear cutting force coefficient function embedded with the novel MUCT is absolutely integrable, making the micro-milling force model more stable and accurate than the conventional models. Moreover, by considering different factors in the MUCT model, the proposed micro-milling force model is more flexible than the traditional models. Micro-milling experiments under different cutting conditions have verified the efficiency and improvement of the proposed micro-milling force model.
Collapse
|
13
|
Hao J, Zhao W, Oh JM, Shen K. A Pillar-Free Diffusion Device for Studying Chemotaxis on Supported Lipid Bilayers. Micromachines (Basel) 2021; 12:mi12101254. [PMID: 34683305 PMCID: PMC8538285 DOI: 10.3390/mi12101254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/15/2021] [Accepted: 10/15/2021] [Indexed: 11/21/2022]
Abstract
Chemotactic cell migration plays a crucial role in physiological and pathophysiological processes. In tissues, cells can migrate not only through extracellular matrix (ECM), but also along stromal cell surfaces via membrane-bound receptor–ligand interactions to fulfill critical functions. However, there remains a lack of models recapitulating chemotactic migration mediated through membrane-bound interactions. Here, using micro-milling, we engineered a multichannel diffusion device that incorporates a chemoattractant gradient and a supported lipid bilayer (SLB) tethered with membrane-bound factors that mimics stromal cell membranes. The chemoattractant channels are separated by hydrogel barriers from SLB in the cell loading channel, which enable precise control of timing and profile of the chemokine gradients applied on cells interacting with SLB. The hydrogel barriers are formed in pillar-free channels through a liquid pinning process, which eliminates complex cleanroom-based fabrications and distortion of chemoattractant gradient by pillars in typical microfluidic hydrogel barrier designs. As a proof-of-concept, we formed an SLB tethered with ICAM-1, and demonstrated its lateral mobility and different migratory behavior of Jurkat T cells on it from those on immobilized ICAM-1, under a gradient of chemokine CXCL12. Our platform can thus be widely used to investigate membrane-bound chemotaxis such as in cancer, immune, and stem cells.
Collapse
Affiliation(s)
- Jia Hao
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA; (J.H.); (W.Z.); (J.M.O.)
| | - Winfield Zhao
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA; (J.H.); (W.Z.); (J.M.O.)
| | - Jeong Min Oh
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA; (J.H.); (W.Z.); (J.M.O.)
| | - Keyue Shen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA; (J.H.); (W.Z.); (J.M.O.)
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA
- USC Stem Cell, University of Southern California, Los Angeles, CA 90033, USA
- Correspondence:
| |
Collapse
|
14
|
Zhou M, Chen Y, Zhang G. Force Prediction and Cutting-Parameter Optimization in Micro-Milling Al7075-T6 Based on Response Surface Method. Micromachines (Basel) 2020; 11:mi11080766. [PMID: 32796514 PMCID: PMC7464037 DOI: 10.3390/mi11080766] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/07/2020] [Accepted: 08/07/2020] [Indexed: 11/16/2022]
Abstract
Optimization of cutting parameters in micro-milling is an important measure to improve surface quality and machining efficiency of the workpiece. Investigation of micro-milling forces prediction plays a positive role in improving machining capacity. To predict micro-milling forces and optimize micro-milling cutting parameters (per-feed tooth (fz), axial cutting depth (ap), spindle speed (n) and tool extended length (l)), a rotatable center composite experiment of micro-milling straight micro-groove in the workpiece of Al7075-T6 were designed, based on second-order response surface methods. According to the experiment results, the least square method was used to estimate the regression coefficient corresponding to the cutting parameters. Simultaneously, the response prediction model of micro-milling was established and successfully coincide the predicted values with the experiment values. The significance of the regression equation was tested by analysis of variance, and the influence of micro-milling cutting parameters on force and top burrs morphology was studied. The experiment results show that in a specific range of cutting parameters, ap and fz have a significant linear relation with the micro-milling force and the top burrs width. According to the optimal response value, the optimized cutting parameters for micro-milling obtained as: n is 11,393 r/min, fz is 6 µm/z, ap is 11 μm and l is 20.8 mm. The research results provide a useful reference for the selection of cutting parameters for micro-milling.
Collapse
Affiliation(s)
| | | | - Guoqing Zhang
- Correspondence: ; Tel.: +86-755-2653-6306; Fax: +86-755-2655-7471
| |
Collapse
|
15
|
Zhang X, Wan Y, Ren B, Wang H, Yu M, Liu A, Liu Z. Preparation of Superhydrophobic Surface on Titanium Alloy via Micro-milling, Anodic Oxidation and Fluorination. Micromachines (Basel) 2020; 11:E316. [PMID: 32192180 PMCID: PMC7143463 DOI: 10.3390/mi11030316] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 03/14/2020] [Indexed: 12/13/2022]
Abstract
The superhydrophobic surface has a great advantage of self-cleaning, inhibiting bacterial adhesion, and enhancing anticoagulant properties in the field of biomedical materials. In this paper, a superhydrophobic surface was successfully prepared on titanium alloy via high-speed micro-milling, anodic oxidation and fluoroalkylsilane modification. The surface morphology was investigated by scanning electron microscope and a laser scanning microscope. The surface wettability was investigated through the sessile-drop method. Firstly, regular microgrooves were constructed by micro-milling. Then, nanotube arrays were fabricated by anodic oxidation. Afterwards, fluoroalkylsilane was used to self-assemble a monolayer on the surface with a composite micro/nanostructure. Compared to polished titanium samples, the modified samples exhibited superhydrophobic properties with the water contact angle (CA) of 153.7° and the contact angle hysteresis of 2.1°. The proposed method will provide a new idea for the construction of superhydrophobic titanium surgical instruments and implants in the future.
Collapse
Affiliation(s)
- Xiao Zhang
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Yi Wan
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Bing Ren
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Hongwei Wang
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Mingzhi Yu
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Anqi Liu
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Zhanqiang Liu
- Key Laboratory of High Efficiency and Clean Manufacturing, School of Mechanical Engineering, Shandong University, Jinan 250061, China; (X.Z.)
- National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| |
Collapse
|
16
|
Chen Y, Wang T, Zhang AG. Research on Parameter Optimization of Micro-Milling Al7075 Based on Edge-Size-Effect. Micromachines (Basel) 2020; 11:E197. [PMID: 32075003 DOI: 10.3390/mi11020197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 01/31/2020] [Accepted: 02/09/2020] [Indexed: 11/17/2022]
Abstract
In the process of micro-milling, the appearance of the edge-size-effect of micro-milling tools cannot be ignored when the cutting parameters are smaller than the cutting edge arc radius (r0) of the micro-milling tool or close to it, and it could easily lead to low cutting efficiency and poor surface quality of the micro-slot. Through micro-milling experiments on Al7075-T6 materials, the change of milling force in the plough zone and shear zone during micro-milling was studied, and the minimum cutting thickness (hmin) range was determined to be 0.2r0–0.4r0 based on r0 of the micro-milling tool. Subsequently, the effect of fz/r0 (fz denotes feed rate per tooth) on the top burr formation of the micro-slot, the surface roughness (Ra) of the micro-slot bottom, and the milling force was studied, and a size-effect band of micro milling was established to determine the strong size-effect zone, transition size-effect zone, and the weak size-effect zone. Finally, two different fz/r0 in the strong size-effect zone and the weak size-effect zone are compared, which proves that the main purpose of the cutting parameters optimization of micro-milling is to avoid cutting parameters locating in the strong edge-size-effect zone. The above conclusions provide a theoretical basis for the selection of micro-milling cutting parameters, and an important reference in improving the surface quality of micro-milling.
Collapse
|
17
|
Cao Z, Ding W, Ma Z, Wang B, Wang Z. Research on the Hydrophobicity of Square Column Structures on Monocrystalline Silicon Fabricated Using Micro-Machining. Micromachines (Basel) 2019; 10:mi10110763. [PMID: 31717942 PMCID: PMC6915655 DOI: 10.3390/mi10110763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/05/2019] [Accepted: 11/09/2019] [Indexed: 11/16/2022]
Abstract
The theoretical prediction models of contact angle were constructed by considering the interface free energy. Then, the square column structure on monocrystalline silicon was fabricated using micro-milling. The rationality of prediction models was validated by regulating the parameters of the square column. It should be mentioned that the whole construction process was facile and efficient. After processing, the hydrophobicity of monocrystalline silicon with the square column structure was improved. The static contact angle of the processed monocrystalline silicon reached 165.8° when the side length of the square column was 60 μm. In addition, the correctness of the prediction models was verified from the perspective of molecular dynamics. The prediction models of contact angle were of great value for the practical application.
Collapse
Affiliation(s)
- Ziyang Cao
- College of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; (W.D.); (Z.M.); (B.W.); (Z.W.)
- Suzhou Key Laboratory of Precision and Efficient Machining Technology, Suzhou 215009, China
- Correspondence: ; Tel.: +86-0512-6832-1707
| | - Wenyu Ding
- College of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; (W.D.); (Z.M.); (B.W.); (Z.W.)
- Suzhou Key Laboratory of Precision and Efficient Machining Technology, Suzhou 215009, China
| | - Zhenwu Ma
- College of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; (W.D.); (Z.M.); (B.W.); (Z.W.)
- Suzhou Key Laboratory of Precision and Efficient Machining Technology, Suzhou 215009, China
| | - Bangfu Wang
- College of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; (W.D.); (Z.M.); (B.W.); (Z.W.)
- Suzhou Key Laboratory of Precision and Efficient Machining Technology, Suzhou 215009, China
| | - Zhongwang Wang
- College of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; (W.D.); (Z.M.); (B.W.); (Z.W.)
- Suzhou Key Laboratory of Precision and Efficient Machining Technology, Suzhou 215009, China
| |
Collapse
|
18
|
Zhang J, Feng C, Wang H, Gong Y. Analytical Investigation of the Micro Groove Surface Topography by Micro-Milling. Micromachines (Basel) 2019; 10:mi10090582. [PMID: 31480437 PMCID: PMC6780784 DOI: 10.3390/mi10090582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022]
Abstract
Micro-milling is an emerging processing technology for machining micro- and high-precision three dimensional parts that require the use of various materials (with sizes ranging from tens of micrometers to a few millimeters) in the field of advanced manufacturing. Therefore, it can be applied to manufacture the micro parts, but new challenges are raised about parts with high surface quality. Herein, both surface formation and micro machined surface roughness models are studied, with the aim of solving complicated problems regarding the quality of surface finish when micro-milling metallic materials. From a theoretical point of view, the first model for surface formation processes considering the strain gradient plasticity theory was built in the area around the cutting edge, and the minimum uncut chip thickness equation was derived. The model accounts for the properties of the work material in tertiary and quaternary zones on the minimum chip thickness. A second model for micro machined surface roughness based on the relationship of kinematics between cutting process and cutter edge was also developed, which takes the influences of tool run out into account. Both proposed models were introduced to analyze the tendency of surface roughness for micro grooves. Both models were also used to justify experimental results. The results show that the developed surface roughness model could be useful in predicting both roughness parameters and trends as a function of cutting parameters.
Collapse
Affiliation(s)
- Jinfeng Zhang
- School of Mechanical Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
| | - Chao Feng
- School of Mechanical Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
| | - Hao Wang
- School of Mechanical Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Yadong Gong
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China
| |
Collapse
|
19
|
Allegri G, Colpani A, Ginestra PS, Attanasio A. An Experimental Study on Micro-Milling of a Medical Grade Co-Cr-Mo Alloy Produced by Selective Laser Melting. Materials (Basel) 2019; 12:E2208. [PMID: 31323945 DOI: 10.3390/ma12132208] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 06/25/2019] [Accepted: 07/05/2019] [Indexed: 11/16/2022]
Abstract
Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys are very promising materials, in particular, in the biomedical field where their unique properties of biocompatibility and wear resistance can be exploited for surgery applications, prostheses, and many other medical devices. While Additive Manufacturing is a key technology in this field, micro-milling can be used for the creation of micro-scale details on the printed parts, not obtainable with Additive Manufacturing techniques. In particular, there is a lack of scientific research in the field of the fundamental material removal mechanisms involving micro-milling of Co-Cr-Mo alloys. Therefore, this paper presents a micro-milling characterization of Co-Cr-Mo samples produced by Additive Manufacturing with the Selective Laser Melting (SLM) technique. In particular, microchannels with different depths were made in order to evaluate the material behavior, including the chip formation mechanism, in micro-milling. In addition, the resulting surface roughness (Ra and Sa) and hardness were analyzed. Finally, the cutting forces were acquired and analyzed in order to ascertain the minimum uncut chip thickness for the material. The results of the characterization studies can be used as a basis for the identification of a machining window for micro-milling of biomedical grade cobalt-chromium-molybdenum (Co-Cr-Mo) alloys.
Collapse
|
20
|
Fu G, Huo D, Shyha I, Pancholi K, Saharudin MS. Experimental Investigation on Micro Milling of Polyester/Halloysite Nano-Clay Nanocomposites. Nanomaterials (Basel) 2019; 9:E917. [PMID: 31247963 DOI: 10.3390/nano9070917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/13/2019] [Accepted: 06/21/2019] [Indexed: 11/24/2022]
Abstract
Efficient machining of the polyester nanocomposite components requires a better understanding of machinability characteristics of such material, which has become an urgent requirement for modern industrial production. In this research, the micro-milling of polyester/halloysite nano-clay (0.1, 0.3, 0.7, 1.0 wt%) nanocomposites were carried out and the outcomes in terms of tool wear, cutting force, the size effect, surface morphology, and surface roughness were compared with those for plain polyester. In order to accomplish the machining of the material in ductile mode, the required feed per tooth was found to be below 0.3 µm. The degree of surface breakage was also found to decrease in ductile mode. A maximum flank wear VB of 0.012 mm after removing 196 mm3 of workpiece material was measured.
Collapse
|
21
|
Sun Z, To S. Effect of Machining Parameters and Tool Wear on Surface Uniformity in Micro-Milling. Micromachines (Basel) 2018; 9:E268. [PMID: 30424201 PMCID: PMC6187721 DOI: 10.3390/mi9060268] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 11/16/2022]
Abstract
In micro-milling, the periodically varying chip thickness, which varies with tool rotation, leads to varying degrees of minimum chip thickness effect and ploughing effect during surface generation. This results in a change of roughness in the cross-sectional direction of the micro-grooves, giving a non-uniform surface quality. However, the factors influencing surface uniformity in micro-milling are not fully understood. In the present work, the effect of the machining parameters and tool wear on surface uniformity in micro-milling is theoretically and experimentally studied. A mathematical model is proposed to predict the varying surface roughness in the cross-sectional direction of the micro-grooves, which is experimentally validated by fabricating a set of 800 µm wide micro-grooves. The theoretical and experimental results reveal that, compared to the normally adopted Ra or Sa, the relative standard deviation of roughness (RSDS) is more appropriate to evaluating surface uniformity. When machining under small feed rates and small cutting depths, the surface uniformity deteriorates as the feed rate increases and improves as the cutting depth increases. The blunt cutting edge induced by tool wear enhances the surface uniformity and increases the surface roughness at the same time. This research furthers understanding of the various cutting mechanisms in micro-milling and can be applied to the optimization of machining parameters in micro-milling.
Collapse
Affiliation(s)
- Zhanwen Sun
- State Key Laboratory in Ultra-Precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.
| | - Suet To
- State Key Laboratory in Ultra-Precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.
| |
Collapse
|
22
|
Kim MJ, Park SC, Rizal B, Guanes G, Baek SK, Park JH, Betz AR, Choi SO. Fabrication of Circular Obelisk-Type Multilayer Microneedles Using Micro-Milling and Spray Deposition. Front Bioeng Biotechnol 2018; 6:54. [PMID: 29868571 PMCID: PMC5958193 DOI: 10.3389/fbioe.2018.00054] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/19/2018] [Indexed: 11/29/2022] Open
Abstract
In this study we present the fabrication of multilayer microneedles with circular obelisk and beveled-circular obelisk geometries, which have potential applications in implantable drug delivery devices. Micro-milling was adopted as an environmental-friendly and cost-effective way to fabricate primary metal microneedle masters. Polylactic acid (PLA) microneedles with sharp tips were then obtained by micromolding followed by oxygen plasma etching and used for preparing polydimethylsiloxane (PDMS) microneedle molds. A spray deposition process was employed for microneedle fabrication to facilitate the formation of multilayer microneedles while helping in maintenance of drug stability. Multilayer microneedles were successfully formed by sequential spraying of poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP) solutions into the mold. The fabricated PLGA-PVP multilayer microneedles penetrated the pig cadaver skin without breakage and released dyes in the skin at different rates, which reveals the potential for implantable microneedles enabling controlled release. Mechanical testing demonstrated that the obelisk-shaped microneedles were mechanically stronger than a pyramid-shaped microneedle and suggested that strong adhesion between PLGA and PVP layers was achieved as well. Structural stability and functionality of a model drug, horseradish peroxidase (HRP), upon spray deposition was examined using circular dichroism (CD) spectroscopy and enzyme activity assay. HRP retained its secondary structure and activity in PVP, whereas HRP in PLGA showed structural changes and reduced activity. Combination of micro-milling and spray deposition would be an attractive way of fabricating drug-containing polymer microneedles with various geometries while reducing prototyping time and process-induced drug instability.
Collapse
Affiliation(s)
- Min Jung Kim
- Department of Anatomy and Physiology, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, KS, United States
| | - Seok Chan Park
- Department of Anatomy and Physiology, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, KS, United States
| | - Binod Rizal
- Department of Anatomy and Physiology, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, KS, United States
| | - Giselle Guanes
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, United States
| | - Seung-Ki Baek
- QuadMedicine R&D Centre, QuadMedicine Co., Ltd, Seongnam, South Korea
| | - Jung-Hwan Park
- Department of BioNano Technology, Gachon BioNano Research Institute, Gachon University, Seongnam, South Korea
| | - Amy R Betz
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, United States
| | - Seong-O Choi
- Department of Anatomy and Physiology, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, KS, United States
| |
Collapse
|
23
|
Bian R, Ferraris E, Ynag Y, Qian J. Experimental Investigation on Ductile Mode Micro-Milling of ZrO₂ Ceramics with Diamond-Coated End Mills. Micromachines (Basel) 2018; 9:E127. [PMID: 30424061 PMCID: PMC6187571 DOI: 10.3390/mi9030127] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/04/2018] [Accepted: 03/12/2018] [Indexed: 11/17/2022]
Abstract
ZrO₂ ceramics are currently used in a broad range of industrial applications. However, the machining of post-sintered ZrO₂ ceramic is a difficult task, due to its high hardness and brittleness. In this study, micro-milling of ZrO₂ with two kinds of diamond-coated end mills has been conducted on a Kern MMP 2522 micro-milling center (Kern Microtechnik GmbH, Eschenlohe, Germany). To achieve a ductile mode machining of ZrO₂, the feed per tooth and depth of cut was set in the range of a few micrometers. Cutting force and machined surface roughness have been measured by a Kistler MiniDynamometer (Kistler Group, Winterthur, Switzerland) and a Talysurf 120 L profilometer (Taylor Hobson Ltd., Leicester, UK), respectively. Machined surface topography and tool wear have been examined under SEM. Experiment results show that the material can be removed in ductile mode, and mirror quality surface with Ra low as 0.02 μm can be achieved. Curled and smooth chips have been collected and observed. The axial cutting force Fz is always bigger than Fx and Fy, and presents a rising trend with increasing of milling length. Tool wear includes delamination of diamond coating and wear of tungsten carbide substrate. Without the protection of diamond coating, the tungsten carbide substrate was worn out quickly, resulting a change of tool tip geometry.
Collapse
Affiliation(s)
- Rong Bian
- Industrial Center, Nanjing Institute of Technology; Nanjing 211167 China.
- Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing University of Aeronautics and Astronautics; Nanjing 210016, China.
| | - Eleonora Ferraris
- Department of Mechanical Engineering, KU Leuven & Member Flanders Make, Leuven 3001, Belgium.
| | - Yinfei Ynag
- Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing University of Aeronautics and Astronautics; Nanjing 210016, China.
| | - Jun Qian
- Department of Mechanical Engineering, KU Leuven & Member Flanders Make, Leuven 3001, Belgium.
| |
Collapse
|
24
|
Ok JT, Choi J, Brown E, Park S. Effect of Different Fluids on Rectified Motion of Leidenfrost Droplets on Micro/Sub-Micron Ratchets. Microelectron Eng 2016; 158:130-134. [PMID: 27721527 PMCID: PMC5053398 DOI: 10.1016/j.mee.2016.04.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Leidenfrost droplets, liquid droplets placed on a hot flat surface above the Leidenfrost temperature of the liquid, are an interesting model system to understand and achieve frictionless motion of droplets on a surface. Controlled unidirectional motion of otherwise random Leidenfrost droplets can be achieved by replacing the flat surface by a surface with topological ratchets. In this study, we show how an increase in the vapor layer thickness below the Leidenfrost droplet influences the droplet motion for underlying ratchets with various periods ranging from 1.5mm down to 800nm. This was exploited by systematically studying the Leidenfrost droplet motion of various liquids with low boiling points including acetone, isopropanol, and R134a on the aforementioned various ratchets. For all liquids with boiling points lower than water, no unidirectional motion was observed for 800 nm. This indicates that the asymmetric vapor flow beneath the Leidenfrost droplet becomes negligible due to the large vapor layer thickness relative to the ratchet depth. However, unidirectional droplet motion was still observed for the micron and millimeter scale ratchets even when the ratchet surface temperature was increased up to 360°C and 230°C for acetone and isopropanol, respectively. This can be attributed to the insulating property of the thick vapor layer which prevent the droplet from producing more vapor with increasing temperature. We also report the effect of the ratchet period on the droplet motion at room temperature using R134a droplets.
Collapse
Affiliation(s)
- Jeong Tae Ok
- McCoy School of Engineering, Midwestern State University, 219C 3410 Taft Blvd., McCoy Hall, Wichita Falls, TX 76308, USA
| | - Junseo Choi
- 2508 Patrick F. Taylor Hall, Mechanical Engineering Department, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Emily Brown
- 2508 Patrick F. Taylor Hall, Mechanical Engineering Department, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Sunggook Park
- 2508 Patrick F. Taylor Hall, Mechanical Engineering Department, Louisiana State University, Baton Rouge, LA 70803, USA
| |
Collapse
|
25
|
Monroy-Vázquez KP, Attanasio A, Ceretti E, Siller HR, Hendrichs-Troeglen NJ, Giardini C. Evaluation of Superficial and Dimensional Quality Features in Metallic Micro-Channels Manufactured by Micro-End-Milling. Materials (Basel) 2013; 6:1434-1451. [PMID: 28809219 PMCID: PMC5452321 DOI: 10.3390/ma6041434] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 03/19/2013] [Accepted: 03/25/2013] [Indexed: 11/16/2022]
Abstract
Miniaturization encourages the development of new manufacturing processes capable of fabricating features, like micro-channels, in order to use them for different applications, such as in fuel cells, heat exchangers, microfluidic devices and micro-electromechanical systems (MEMS). Many studies have been conducted on heat and fluid transfer in micro-channels, and they appeared significantly deviated from conventional theory, due to measurement errors and fabrication methods. The present research, in order to deal with this opportunity, is focused on a set of experiments in the micro-milling of channels made of aluminum, titanium alloys and stainless steel, varying parameters, such as spindle speed, depth of cut per pass (ap), channel depth (d), feed per tooth (fz) and coolant application. The experimental results were analyzed in terms of dimensional error, channel profile shape deviation from rectangular and surface quality (burr and roughness). The micro-milling process was capable of offering quality features required on the micro-channeled devices. Critical phenomena, like run-out, ploughing, minimum chip thickness and tool wear, were encountered as an explanation for the deviations in shape and for the surface quality of the micro-channels. The application of coolant and a low depth of cut per pass were significant to obtain better superficial quality features and a smaller dimensional error. In conclusion, the integration of superficial and geometrical features on the study of the quality of micro-channeled devices made of different metallic materials contributes to the understanding of the impact of calibrated cutting conditions in MEMS applications.
Collapse
Affiliation(s)
| | - Aldo Attanasio
- Department of Industrial and Mechanical Engineering, University of Brescia, Via Branze, Brescia 38-25123, Italy.
| | - Elisabetta Ceretti
- Department of Industrial and Mechanical Engineering, University of Brescia, Via Branze, Brescia 38-25123, Italy.
| | - Héctor R Siller
- Tecnológico de Monterrey, Eugenio Garza Sada 2501 Sur, Monterrey, NL 64849, Mexico.
| | | | - Claudio Giardini
- Department of Engineering, University of Bergamo, Via Marconi, Dalmine 5-24044, Italy.
| |
Collapse
|
26
|
Abstract
Two lens arrays of 20 lenses (4×5) are fabricated in polystyrene (Rexolite 1422) using a 3-D, three-axis micromilling process. The lenses of one array are concave (R(curv) = -2 mm) and the lenses of the other array are convex (R(curv) = 2 mm). A method for correcting a 3-D micromilling program for a single lens is described and evaluated. The lens separation is 4 mm and Ø(diam) = 2.6 mm for all lenses. Based on a measurement of key optical parameters (radius error, wavefront error, and surface roughness), micromilled lenses are shown to be of high optical quality compared with the form error and surface roughness obtained with plastic injection molded lenses.
Collapse
Affiliation(s)
- Brian McCall
- Rice University Department of Bioengineering Houston, Texas 77030
| | | |
Collapse
|