3D Printed Acoustically Programmable Soft Microactuators

Tri-Prism Origami Enabled Soft Modular Actuator for Reconfigurable Robots

Soft actuators hold great potential for applications in surgical operations, robotic manipulation, and prosthetic devices. However, they are limited by their structures, materials, and actuation methods, resulting in disadvantages in output force and dynamic response. This article introduces a soft pneumatic actuator capable of bending based on triangular prism origami. The origami creases are crafted by utilizing fabrics to gain swift response and fatigue-resistant properties. By connecting two actuators in series, combined motions including extension and diversified compound bending can be achieved, facilitating control in complex scenarios. After modularizing the soft actuator via mortise and tenon structures, several actuators can be programmed to execute a variety of intricate tasks by adjusting the timing sequences of their contraction and expansion. We showcase its applications in reconfigurable robots, and the results confirm that such a design is adequate for flexibly performing tasks such as soft gripping, navigational movement, and obstacle avoidance. These findings highlight the significance of our actuator in developing soft robots for versatile tasks.

State of the Art in Actuation of Micro/Nanorobots for Biomedical Applications

The emergence of micro/nanorobotics stands poised to revolutionize various biomedical applications, given its potential to offer precision, reduced invasiveness, and enhanced functionality. In the face of such potential, understanding the mechanisms that drive these tiny robots, especially their actuation techniques, becomes critical. Although there is a surge in research dedicated to micro/nanorobotics, there exists a gap in consolidating the diverse actuation strategies and their suitability for biomedical applications. This comprehensive review seeks to bridge this gap by providing an in-depth evaluation of the current actuation techniques employed by micro/nanorobots, particularly emphasizing their relevance and potential for clinical translation. The discussion starts by elucidating the different actuation strategies, ranging from magnetic, electric, acoustic, light-based, to chemical and biological mechanisms. Then, various examples and meticulous assessment of each technique are offered, spotlighting their respective merits and limitations within a biomedical context. This review illuminates the transformative capabilities of these actuation methods in medicine. It not only highlights the progress made in this burgeoning field but also underscores the areas that require further exploration and development.

SonoTransformers: Transformable acoustically activated wireless microscale machines

Shape transformation, a key mechanism for organismal survival and adaptation, has gained importance in developing synthetic shape-shifting systems with diverse applications ranging from robotics to bioengineering. However, designing and controlling microscale shape-shifting materials remains a fundamental challenge in various actuation modalities. As materials and structures are scaled down to the microscale, they often exhibit size-dependent characteristics, and the underlying physical mechanisms can be significantly affected or rendered ineffective. Additionally, surface forces such as van der Waals forces and electrostatic forces become dominant at the microscale, resulting in stiction and adhesion between small structures, making them fracture and more difficult to deform. Furthermore, despite various actuation approaches, acoustics have received limited attention despite their potential advantages. Here, we introduce "SonoTransformer," the acoustically activated micromachine that delivers shape transformability using preprogrammed soft hinges with different stiffnesses. When exposed to an acoustic field, these hinges concentrate sound energy through intensified oscillation and provide the necessary force and torque for the transformation of the entire micromachine within milliseconds. We have created machine designs to predetermine the folding state, enabling precise programming and customization of the acoustic transformation. Additionally, we have shown selective shape transformable microrobots by adjusting acoustic power, realizing high degrees of control and functional versatility. Our findings open new research avenues in acoustics, physics, and soft matter, offering new design paradigms and development opportunities in robotics, metamaterials, adaptive optics, flexible electronics, and microtechnology.