Conductive hydrogels have been widely used in soft robotics, as well as skin-attached and implantable bioelectronic devices. Among the candidates of conductive fillers, conductive polymers have become popular due to their intrinsic conductivity, high biocompatibility, and mechanical flexibility. However, it is still a challenge to construct conductive polymer-incorporated hydrogels with a good performance using a facile method. Herein, we present a simple method for the one-pot preparation of conductive polymer-incorporated hydrogels involving rapid photocuring of the hydrogel template followed by slow in situ polymerization of pyrrole. Due to the use of a milder oxidant, hydrogen peroxide, for polypyrrole synthesis, the photocuring of the hydrogel template and the growing of polypyrrole proceeded in an orderly manner, making it possible to prepare conductive polymer-incorporated hydrogels in one pot. The preparation process is facile and extensible. Moreover, the obtained hydrogels exhibit a series of properties suitable for biomedical strain sensors, including good conductivity (2.49 mS/cm), high stretchability (>200%), and a low Young’s modulus (~30 kPa) that is compatible with human skin.

Fluid actuated cellular structures are morphing structures inspired by the nastic movement of plants. These materials have a wide array of applications from morphing aircraft wings to soft robotics. The nonlinear shape-morphing behaviors of the fluid actuated cellular structures composed of randomly distributed polygonal motor cells are investigated in this work. A new multiscale modeling framework based on multiscale finite-element methods is proposed to simulate the nonlinear behaviors of such adaptive materials with irregular polygonal microstructures. The multiscale displacement and hydraulic pressure base functions are firstly constructed to establish the relationship between the microstructures of the fluidic actuating cells and the macroscopic deformation on the polygonal coarse-scale mesh. Then, the corotational formulation for geometrically nonlinear analysis is integrated to this multiscale method to decompose the nonlinear deformations of the polygonal coarse-grid element into rigid-bod...