Microfluidic Packaging Integration with Electronic-Photonic Biosensors Using 3D Printed Transfer Molding

Understanding the Current Distribution and Mass Transport Properties in 3D-Printed Architected Flow-Through Electrodes

Architected materials offer promising advancements in energy storage by enabling highly customizable, high-surface-area, ordered, and low-defect porous structures. This study investigates the current distribution and mass transport within complex 3D-printed lattice electrodes under flow-through conditions. Conductive lattices were fabricated using microstereolithography followed by pyrolytic carbonization. Lattice geometry effects were analyzed by varying the unit cell type [simple cubic (SC), body- and face-centered cubic (BCC/FCC), IsoTruss, and Octet], porosity, and current density. Current distribution uniformity was investigated using a model high-efficiency copper deposition reaction. Local film thickness distributions were predicted using a numerical model and validated experimentally using micro-X-ray computed tomography. Scaling relationships for informing electrochemical reaction conditions and current uniformity are formulated as a modified lattice-based Wagner number (Wa Lattice) and a corresponding inverse Damkohler number (Da Lattice -1). Validated models reveal that mass-transfer coefficients scale as Octet > IsoTruss > FCC ∼ BCC > SC. Inertial effects become significant at Reynolds number Re > 3 and are particularly pronounced in Octet structures due to an abundance of struts oriented away from the fluid flow direction. The study underscores the importance of electrode engineering and process conditions necessary to tailor mass transport and current uniformities to various device applications.

A review on the surface modification of materials for 3D-printed diagnostic devices

Three-dimensional (3D) printing in tissue engineering and biosensing of analytes by using biocompatible materials or modifying surface structures is an upcoming area of study. This review discusses three common surface modification techniques, viz. alkaline hydrolysis, UV light photografting, and plasma treatment. Alkaline hydrolysis involves the reaction of an alkaline solution with the surface of a material, causing the surface to develop carboxyl and hydroxyl groups. This technique can enhance the biocompatibility, surface wettability, adhesion, printability, and dyeability of materials, such as acrylonitrile butadiene styrene (ABS), polycarbonate, and polylactic acid (PLA). This review also mentions details about some of the surface-modified 3D-printed diagnostic devices. Although most of the devices are modified using chemical processes, there are always multiple techniques involved while designing a diagnostic device. We have, therefore, mentioned some of the devices based on the materials used instead of categorising them as per modification techniques. 3D printing helps in the design of sophisticated shapes and structures using multiple materials. They can, therefore be used even in the design of microfluidic devices that are very useful for biosensing. We have also mentioned a few materials for printing microfluidic devices.

Low-loss silicon nitride photonic ICs for near-infrared wavelength bandwidth

Low-loss photonic integrated circuits (PICs) are the key elements in future quantum technologies, nonlinear photonics and neural networks. The low-loss photonic circuits technology targeting C-band application is well established across multi-project wafer (MPW) fabs, whereas near-infrared (NIR) PICs suitable for the state-of-the-art single-photon sources are still underdeveloped. Here, we report the labs-scale process optimization and optical characterization of low-loss tunable photonic integrated circuits for single-photon applications. We demonstrate the lowest propagation losses to the date (as low as 0.55 dB/cm at 925 nm wavelength) in single-mode silicon nitride submicron waveguides (220×550 nm). This performance is achieved due to advanced e-beam lithography and inductively coupled plasma reactive ion etching steps which yields waveguides vertical sidewalls with down to 0.85 nm sidewall roughness. These results provide a chip-scale low-loss PIC platform that could be even further improved with high quality SiO₂ cladding, chemical-mechanical polishing and multistep annealing for extra-strict single-photon applications.

3D Printing Technologies in Biosensors Production: Recent Developments

Recent advances in 3D printing technologies and materials have enabled rapid development of innovative sensors for applications in different aspects of human life. Various 3D printing technologies have been adopted to fabricate biosensors or some of their components thanks to the advantages of these methodologies over the traditional ones, such as end-user customization and rapid prototyping. In this review, the works published in the last two years on 3D-printed biosensors are considered and grouped on the basis of the 3D printing technologies applied in different fields of application, highlighting the main analytical parameters. In the first part, 3D methods are discussed, after which the principal achievements and promising aspects obtained with the 3D-printed sensors are reported. An overview of the recent developments on this current topic is provided, as established by the considered works in this multidisciplinary field. Finally, future challenges on the improvement and innovation of the 3D printing technologies utilized for biosensors production are discussed.