Bioelectronics Integrated on 3D Skin Surfaces via Kirigami-Structured Nanofibrous Membranes and Transfer-Printed Microsensors

Skin-integrated soft electronics have attracted extensive research attention due to their potential utility for fitness monitoring, disease management, human-machine interfaces, and other applications. Although many materials and device components were explored for the construction of skin-integrated systems, achieving multifunctional sensor platform combined with good breathability, conformability and robustness on the skin remains difficult. Herein, two platforms were built for 3D interfaces between bioelectronics and the skin. Firstly, breathable and conformal electronic membranes (BCEMs) were manufactured with hybrid integration of microfabricated multifunctional sensors and kirigami-structured nanofibrous substrates. The resulting membrane devices exhibit tissue-like mechanical properties with high permeability for vapor transport. In addition, kirigami structures can be introduced into these membranes, providing high stretchability and 3D conformability for large-area integration on the skin. In the second scheme, tough and permeable aramid nanofiber- polyvinyl alcohol (ANF-PVA) membranes were introduced to build robust kirigami electronics. The nanofiber composite endows high fracture toughness of kirigami membranes, which can prevent failure of kirigami membranes upon stretching due to crack propagation. Energy release rate were calculated by finite element analysis (FEA) to evaluate the robustness of kirigami membranes. Microfabricated sensors and conductive polymers were employed to be the electronic components of kirigami electronics. The multifunctional sensors array from these two platforms allowed for spatiotemporal measurement of bioelectrical signals, temperature, skin hydration, and potentially many other physiological parameters. The robust performance and manufacturing scalability provided by these multifunctional skin electronics may create further opportunities for the development of advanced wearable systems.