The growing need for the implementation of stretchable biosensors in the human body and organ systems has driven a new rapid prototyping scheme through the direct ink writing (DIW) of multidimensional functional architectures in an arbitrary shape and size to meet the requirement of adapting the geometric nonlinearity of a specific biological site. Recent approaches involve the use of biocompatible viscoelastic inks that are dispensable through an automated nozzle injection system. However, their pragmatic application remains challenged in particular medical practices that demand long-term reliable recording under periodic large strain cycles, such as the cardiac cycle, due to their viscoelastic nature that produces both mechanical and electrical hysteresis. Herein, we report a new class of a poroelastic silicone composite that is adaptable for high-precision DIW of a custom-designed biosensor, which is exceptionally soft and insensitive to mechanical strain without generating significant hysteresis. The unique structural property of the composite material yields a robust and seamless coupling to living tissues, thereby enabling both high-fidelity recording of spatiotemporal electrophysiological activity and real-time ultrasound imaging for visual feedback. In vivo evaluation of a custom-fit biosensor in a murine acute myocardial infarction model demonstrates a potential clinical utility in the simultaneous intraoperative recording and imaging on the epicardial surface, which may guide a definitive surgical treatment.