Recent developments in stretchable electronics hold promise to advance wearable technologies for health monitoring. Emerging techniques allow soft materials to serve as substrates and packaging for electronics, enabling devices to comply with and conform to the body, unlike conventional rigid electronics. However, few stretchable electronic devices achieve the high integration densities that are possible using conventional substrates, such as printed rigid or flexible circuit boards. Here, a new manufacturing method is presented for wearable soft health monitoring devices with high integration densities. It is shown how to fabricate soft electronics on rigid carrier substrates using microfabrication techniques in tandem with strain relief features. Together, these make it possible to integrate a large variety of surface mount components in complex stretchable circuits on thin polymer substrates. The method is largely compatible with existing industrial manufacturing processes. The promise of these methods is demonstrated by realizing skin‐interfaced devices for multimodal physiological data capture via multiwavelength optoelectronic sensor arrays comprised of light emitting diodes and phototransistors. The devices provide high signal‐to‐noise ratio measurements of peripheral hemodynamics, illustrating the promise of soft electronics for wearable health monitoring applications.
Recyclable and biodegradable microelectronics, i.e., “green” electronics, are emerging as a viable solution to the global challenge of electronic waste. Specifically, flexible circuit boards represent a prime target for materials development and increasing the utility of green electronics in biomedical applications. Circuit board substrates and packaging are good dielectrics, mechanically and thermally robust, and are compatible with microfabrication processes. Poly(octamethylene maleate (anhydride) citrate) (POMaC) – a citric acid-based elastomer with tunable degradation and mechanical properties – presents a promising alternative for circuit board substrates and packaging. Here, we report the characterization of Elastomeric Circuit Boards (ECBs). Synthesis and processing conditions were optimized to achieve desired degradation and mechanical properties for production of stretchable circuits. ECB traces were characterized and exhibited sheet resistance of 0.599 Ω cm−2, crosstalk distance of <0.6 mm, and exhibited stable 0% strain resistances after 1000 strain cycles to 20%. Fabrication of single layer and encapsulated ECBs was demonstrated.more » « less
- Award ID(s):
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- Publisher / Repository:
- Nature Publishing Group
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- Journal Name:
- npj Flexible Electronics
- Medium: X
- Sponsoring Org:
- National Science Foundation
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