Development of efficient signal processing bioinspired sensor and highly stretchable electronics platform

Abstract

Soft electronics have received a great deal of interest due to their pivotal role in healthcare and biomedical devices, soft robotics, and human-machine interfaces. Although many stretchable electronics comprising rigid components (e.g., chips, LED, battery) and stretchable polymer have been developed, interfacial delamination due to mechanical mismatch under various kinds of deformations hinders their practicality. Here, we controlled stress distribution at the interface using puzzle-shaped rigid islands and porous structured soft polymeric matrix. Compared to the shape of conventional rigid islands, the use of the puzzle-shape can drastically improve mechanical stability under different deformation modes (e.g., twisting, shearing, crumpling) without the failure of the electronics. This improvement is attributed to the local curvatures of the pattern exhibiting larger delamination resistance. In addition, islands were hexagonally packed to maximize chip density, and the pores were distributed throughout the soft polymeric structure to reduce the stress on the rigid region by 85%, thereby enhancing stretchability. And a device that mimics a mechanical sensory receptor is a new concept synaptic device that generates a digital signal by itself from a sensor that outputs an existing analog signal. These results are also applicable to various functional soft materials (e.g., liquid crystal elastomer, hydrogel, Ecoflex, Dragon skin, and porous carbon nanotube (CNT) - Ecoflex composite). Our approach provides guidance toward the practical applications of stretchable electronics by solving mechanical durability issues under various deformation modes.