A New Class of Single-Material, Non-Reciprocal Microactuators

0566563 - ÚOCHB 2024 RIV DE eng J - Journal Article
Maslen, C. - Gholamipour-Shirazi, A. - Butler, M. D. - Kropáček, J. - Řehoř, Ivan - Montenegro-Johnson, T.
A New Class of Single-Material, Non-Reciprocal Microactuators.
Macromolecular Rapid Communications. Roč. 44, č. 6 (2023), č. článku 2200842. ISSN 1022-1336. E-ISSN 1521-3927
Institutional support: RVO:61388963
Keywords : asymmetric * hydrogels * in-plane anisotropy * micro-actuators * non-reciprocity * soft robots
OECD category: Chemical process engineering
Impact factor: 4.6, year: 2022
Method of publishing: Open access
https://doi.org/10.1002/marc.202200842

A crucial component in designing soft actuating structures with controllable shape changes is programming internal, mismatching stresses. In this work, a new paradigm for achieving anisotropic dynamics between isotropic end-states—yielding a non-reciprocal shrinking/swelling response over a full actuation cycle—in a microscale actuator made of a single material, purely through microscale design is demonstrated. Anisotropic dynamics is achieved by incorporating micro-sized pores into certain segments of the structures, by arranging porous and non-porous segments (specifically, struts) into a 2D hexagonally-shaped microscopic poly(N-isopropyl acrylamide) hydrogel particle, the rate of isotropic shrinking/swelling in the structure is locally modulated, generating global anisotropic, non-reciprocal, dynamics. A simple mathematical model is introduced that reveals the physics that underlies these dynamics. This design has the potential to be used as a foundational tool for inducing non-reciprocal actuation cycles with a single material structure, and enables new possibilities in producing customized soft actuators and modular anisotropic metamaterials for a range of real-world applications, such as artificial cilia.
Permanent Link: https://hdl.handle.net/11104/0337879