(542g) Fabrication and Applications of 3D Printed Thermoresponsive Gel Crawlers

The ability to create biomimetic locomotive and shape-changing structures is important for diverse fields of robotics, drug delivery, and biomedical devices. Previously, a variety of stimuli-responsive materials, particularly hydrogels, have been used to create devices that respond to pH, temperature, light, and even biochemicals. Yet, creating untethered soft locomotors that can move autonomously in response to stimuli cycles on flat surfaces has been challenging.

Inspired by peristaltic locomotion in inchworms, we have previously developed autonomous gel crawlers that can spontaneously break symmetry and locomote based on an asymmetry in swelling, morphology, and, consequently, contact forces.¹ The gel crawlers were 3D printed using inks of an active thermoresponsive poly (N-isopropyl acrylamide) (pNIPAM) and passive polyacrylamide (pAAM) with a suspended linker. Here, we describe such crawlers and discuss advances in design, miniaturization, and applications such as chemical and drug delivery.

¹ Pantula A, Datta B, Shi Y, Wang M, Liu J, Deng S, Cowan NJ, Nguyen TD, Gracias DH. Untethered unidirectionally crawling gels driven by asymmetry in contact forces.; Science Robotics, 7, 73, 3add2903 (2022).