Micro-Lifting Jack: Heat- and Light-Fueled 3D Symmetric Deformation of Bragg-Onion-Like Beads with Fully Polymerized Chiral Networks

The dynamic control of anisotropic geometric deformation in key soft materials can provide multifunctional advantages for smart devices, thereby expanding the scope of application. The core value of harnessing the physical multiresponsiveness of soft matter is to control the shape, size, and direction of its deformation. This study reports the thermal- and photoreversible symmetrical deformation and structural color change of 3D Bragg-onion-like fully polymerized cholesteric liquid crystal (CLC) beads mass-produced by microfluidics. A jack-inspired soft microdevice comprising durable fully polymerized CLC beads by the stand-alone and free of extraction technique is demonstrated to have the unique photoresponsive capabilities of lifting substantially heavy objects and photochromatism via light-triggered symmetric volume expansion of the CLC beads. The monomer order is maintained upon photopolymerization, and the complex director patterns of the radially arranged helical pitch under planar confinement are frozen-in. The desired symmetrical volume expansion with photochromatic property is realized by decreasing the degree of the order parameter, which is caused by the reorientation of the liquid crystal director. This study provides a platform for demonstrating the heat- and light-responsive bead-based smart devices and their applicability in advanced optomechanical integrated microsystems and multiresponsive Fabry-Perot resonator.