An anti-impact principle for skin-interfaced devices with a layered structure

Abstract

Skin-interfaced electromechanical and microfluidic devices hold significant potential for healthcare monitoring in real-world scenarios. However, their vulnerability to physical impacts on the human body can result in device deformation and measurement inaccuracies or damage, necessitating the establishment of an anti-impact principle and quantitative criterion to assess their impact resistance. In this study, we propose an anti-impact theoretical approach for skin-interfaced devices, whereby the main electronic components layer is encapsulated between elastomeric layers modeled as transversely isotropic-elastic mediums. Our methodology utilizes an equation of state variables and the transfer matrix method to obtain a general solution under impact conditions. We also discuss several parameters related to the impact resistance of the layered structure, including the thickness, elastic modulus, density, and size, and introduce an impact resistance coefficient to ensure device stability. Our approach is validated through finite element analysis and experimental observations, demonstrating improved durability and reliability for next-generation epidermal devices capable of withstanding harsh physical environments such as contact sports and high-intensity sports.