Cardiomyocyte-Driven Structural Color Actuation in Anisotropic Inverse Opals

Biohybrid actuators composed of living tissues and artificial materials have attracted increasing interest in recent years because of their extraordinary function of dynamically sensing and interacting with complex bioelectrical signals. Here, a compound biohybrid actuator with self-driven actuation and self-reported feedback is designed based on an anisotropic inverse opal substrate with periodical elliptical macropores and a hydrogel filling. The benefit of the anisotropic surface topography and high biocompatibility of the hydrogel is that the planted cardiomyocytes could be induced into a highly ordered alignment with recovering autonomic beating ability on the elastic substrate. Because of the cell elongation and contraction during cardiomyocyte beating, the anisotropic inverse opal substrates undergo a synchronous cycle of deformation actuations, which can be reported as corresponding shifts of their photonic band gaps and structural colors. These self-driven biohybrid actuators could be used as elements for the construction of a soft-bodied structural color robot, such as a biomimetic guppy with a swinging tail. Besides, with the integration of a self-driven biohybrid actuator and microfluidics, the advanced heart-on-a-chip system with the feature of microphysiological visuality has been developed for integrated cell monitoring and drug testing. This anisotropic inverse opal-derived biohybrid actuator could be widely applied in biomedical engineering.