Inflammation-free, gas-permeable, lightweight, stretchable on-skin electronics with nanomeshes

Abstract

Thin-film electronic devices can be integrated with skin for health monitoring and/or for interfacing with machines. Minimal invasiveness is highly desirable when applying wearable electronics directly onto human skin. However, manufacturing such on-skin electronics on planar substrates results in limited gas permeability. Therefore, it is necessary to systematically investigate their long-term physiological and psychological effects. As a demonstration of substrate-free electronics, here we show the successful fabrication of inflammation-free, highly gas-permeable, ultrathin, lightweight and stretchable sensors that can be directly laminated onto human skin for long periods of time, realized with a conductive nanomesh structure. A one-week skin patch test revealed that the risk of inflammation caused by on-skin sensors can be significantly suppressed by using the nanomesh sensors. Furthermore, a wireless system that can detect touch, temperature and pressure is successfully demonstrated using a nanomesh with excellent mechanical durability. In addition, electromyogram recordings were successfully taken with minimal discomfort to the user.

Untethered soft robotics

“…The electrical resistance of these materials is dependent on the contact area between particles, which can vary with deformation. As a result, nanomaterials can be made into robust resistive strain or pressure sensors [82][83][84][85] , and can thus be used to locate applied stress 86 . These sensors are often well-suited for wearable devices and can be used to determine end-effector position and joint angles 87 , or to translate the American Sign Language alphabet 88 .…”

“…These sensors are often well-suited for wearable devices and can be used to determine end-effector position and joint angles 87 , or to translate the American Sign Language alphabet 88 . Mesh structures formed from gold and polyvinyl alcohol can be fabricated directly onto the skin, thereby ensuring gas-permeability while forming conductive traces and sensors that can measure finger bending and muscle activity 82 (Fig. 4e).…”

Transparent arrays of bilayer-nanomesh microelectrodes for simultaneous electrophysiology and two-photon imaging in the brain

“…Nanomeshed forms of conductors have emerged as an encouraging biocompatible material for future soft bioelectronics ( 23 , 24 ). Recently, we demonstrated an innovative bilayer-nanomesh approach by reliably stacking individual layers of metal and low-impedance coating—the exact materials used in modern MEAs—in the same nanomeshed pattern and achieved system-level high performance including microelectrode impedance, charge injection limit, and transparency ( 25 ).…”

Deployment and exploitation of nanotechnology nanomaterials and nanomedicine

“…A substrate-free nanoelectronic mesh has been produced that can be directly laminated onto the skin and is ultrathin, stretchable, highly gas-permeable and inflammation-free. It was shown to provide faithful electromyogram recordings and may be engineered to detect touch, temperature and pressure, and to relay signals wirelessly [123]. A wearable stretchable patch for diabetes monitoring and feedback therapy has been realised combining nanostructured graphene and a gold mesh.…”