Scalable manufacturing of microactuators with heterogeneous materials, such as bilayer hydrogels, remains a challenge for soft robotics in collective intelligence and micromanipulation. Current methods, like manual assembly and three-dimensional (3D) printing, limit scalability and result in bulky devices with slow actuation. We present a precise, parallel strategy─macroscopic supramolecular assembly (MSA)─that enables large-scale production of microactuators with rapid response. Using the widely studied thermos-responsive poly(N-isopropylacrylamide) (PNIPAM)/polyacrylamide (PAAm) system, we apply the noncovalent interfacial links between β-cyclodextrin (CD) and adamantane (Ad) groups to fabricate PNIPAM/PAAm microactuators. PNIPAM-CD microhydrogel arrays on a donor substrate are "picked" and "placed" onto PAAm-Ad microhydrogels using a mask aligner to control the precision. In-situ measurements of interfacial forces confirm that MSA kinetics favor adhesion control and dynamic binding/debonding modeling reveals the interfacial interactive mechanism. The microactuators show an ultrafast response (0.25 s) and complete deformation in 1.17 s─almost 2 orders of magnitude faster than macroscopic counterparts─due to enhanced mass and heat transfer at the microscale. This strategy provides a scalable route for parallel fabrication of miniaturized devices with rapid, reliable actuation.
Liu et al. (Fri,) studied this question.