Epidermal Electronics

Abstract

We report classes of electronic systems that achieve thicknesses, effective elastic moduli, bending stiffnesses, and areal mass densities matched to the epidermis. Unlike traditional wafer-based technologies, laminating such devices onto the skin leads to conformal contact and adequate adhesion based on van der Waals interactions alone, in a manner that is mechanically invisible to the user. We describe systems incorporating electrophysiological, temperature, and strain sensors, as well as transistors, light-emitting diodes, photodetectors, radio frequency inductors, capacitors, oscillators, and rectifying diodes. Solar cells and wireless coils provide options for power supply. We used this type of technology to measure electrical activity produced by the heart, brain, and skeletal muscles and show that the resulting data contain sufficient information for an unusual type of computer game controller.

Recent Progress on Piezoelectric and Triboelectric Energy Harvesters in Biomedical Systems

“…D) A self‐powered neural differentiation system with a step‐driven TENG as the electrical simulation power source. Reproduced with permission 106. Copyright 2016, American Chemistry Society.…”

“…Guo et al combined a highly electrically conductive rGO−PEDOT hybrid scaffold with a step‐driven TENG as the electrical simulation power source to build a self‐powered neural differentiation system 106. The electrical outputs of 250 V and 30 µA were achieved by driving the TENG with human step motion, which was sufficient to stimulate the MSC cells.…”

Blending Electronics with the Human Body: A Pathway toward a Cybernetic Future

“…In recent years, they have also been integrated into a great variety of organic polymer matrices to yield multifunctional flexible devices with improved electrophysiological sensing capabilities 284, 339, 434. Notably, these properties and functionalities of inorganic components are greatly affected by their crystal structure, phase, size, shape, and their chemical attributes 217.…”

“…Therefore, conformal bioelectronics that enables real‐time monitoring of the mechanical properties of skin can be used to detect potentially life‐threatening and chronic diseases in the home rather than in the clinic 290, 291. Over the years a wide‐range of these so‐called “e‐skin” devices have been developed for healthcare monitoring purposes 12, 62, 284, 289, 292, 293. In simple terms, e‐skin devices are flexible sensing networks with accurate spatial mapping and detection capabilities that enable unmatched recordings of the mechanical metrics of skin.…”

Biomimicking Topographic Elastomeric Petals (E‐Petals) for Omnidirectional Stretchable and Printable Electronics

“…The booming of research in ultraflexible, stretchable, and wearable electronics in the past decade has witnessed the remarkable development of advanced materials,1, 2, 3 structures,4, 5, 6, 7, 8, 9 and devices10, 11, 12, 13, 14, 15, 16, 17, 18, 19 that can function under large tensile strains (1%). In particular, the realization of highly conductive and stretchable metal interconnects, contacts, and electrodes are recognized as one critical milestone for these thin film devices 2, 13, 20, 21, 22, 23, 24.…”