Fabrication and Functionality Integration Technologies for Small‐Scale Soft Robots

Abstract

Small‐scale soft robots are attracting increasing interest for visible and potential applications owing to their safety and tolerance resulting from their intrinsic soft bodies or compliant structures. However, it is not sufficient that the soft bodies merely provide support or system protection. More importantly, to meet the increasing demands of controllable operation and real‐time feedback in unstructured/complicated scenarios, these robots are required to perform simplex and multimodal functionalities for sensing, communicating, and interacting with external environments during large or dynamic deformation with the risk of mismatch or delamination. Challenges are encountered during fabrication and integration, including the selection and fabrication of composite/materials and structures, integration of active/passive functional modules with robust interfaces, particularly with highly deformable soft/stretchable bodies. Here, methods and strategies of fabricating structural soft bodies and integrating them with functional modules for developing small‐scale soft robots are investigated. Utilizing templating, 3D printing, transfer printing, and swelling, small‐scale soft robots can be endowed with several perceptual capabilities corresponding to diverse stimulus, such as light, heat, magnetism, and force. The integration of sensing and functionalities effectively enhances the agility, adaptability, and universality of soft robots when applied in various fields, including smart manufacturing, medical surgery, biomimetics, and other interdisciplinary sciences.

3D-Stereolithographically Printed Mesoscopic Microgels with Precisely Positioned Supramolecular Recognition Motifs─Soft Building Blocks for Assembly and Light Triggered Disassembly

“…2,3 Due to the wide variety of employable resists and the high resolution of the obtained structures, the applications of stereolithographically patterned materials range from pharmaceutical delivery vehicles, 4 to tissue scaffolds and medical implants, 5,6 and mesoscopic soft robotics. 7 Soft robotics typically require materials that are elastic and flexible. Hydrogels, 3D cross-linked polymer networks that can be swollen in water, represent a class of materials with such properties.…”

“…However, in stereolithography, the produced structure is withdrawn from the illumination zone after curing, allowing illumination and printing of another photolithographically patterned layer. As such, stereolithography represents a powerful additive manufacturing technique that produces 3D objects with smooth surfaces and sharp and precise edges. , Due to the wide variety of employable resists and the high resolution of the obtained structures, the applications of stereolithographically patterned materials range from pharmaceutical delivery vehicles, to tissue scaffolds and medical implants, , and mesoscopic soft robotics . Soft robotics typically require materials that are elastic and flexible.…”

“…Stereolithography offers 3D patterning, andbeing a sequential lithography processin principle, it could give access to printed structures that are composed of several different materials. As such, stereolithography has been employed to print mesoscopic microgels with precise dimensions and of complex structures; however, 3D patterning of the material properties and different functionalities is currently not attainable using stereolithographic techniques. ,− …”

Microelectronic Morphogenesis: Smart Materials with Electronics Assembling into Artificial Organisms

“…Living technology-technology invested with the informationcontrolled sustainable self-x properties of living systems, like makes use of silicon chips to control complex machine modules able to self-assemble and change their shapes, but the large size (and cost) of modules limits their ability to exploit selfx properties. Soft modular robotics has been a major focus of recent developments [6][7][8][9] but integration with electronic control and downscaling of modules have lagged. This Perspective article addresses the advances in technology that are enabling a radical downscaling of modular robotics to use smart microscopic modules with on board microelectronics, and in particular advances that are projecting such systems towards a low module size, high flexibility, and high information-control subdomain in which microelectronic morphogenesis becomes possible: the generation of organism-like structural complexity through the self-folding and self-assembly of microelectronically active micromodules.…”

Materializing Autonomy in Soft Robots across Scales

“…[29] Moreover, at decreasing length scales soft robots and active matter systems can be too small to host standard circuitry and power sources, making any onboard computation prohibitively challenging. [30][31][32] Despite these fundamental engineering challenges, the integration of information-processing within physically intelligent material substrates is crucial to realizing autonomy in soft robots at all scales. [33][34][35][36] To make matters worse, soft robotic control strategies do not-and will likely never-generalize in the same way as traditional robot control.…”