Scaling Metal‐Elastomer Composites toward Stretchable Multi‐Helical Conductive Paths for Robust Responsive Wearable Health Devices. Issue 17 (17th July 2021)

• Record Type: Journal Article
• Authors: Zhao, Yue; Tan, Yu Jun; Yang, Weidong; Ling, Shaohua; Yang, Zijie; Teo, Ju Teng; See, Hian Hian; Lee, David Kwok Hung; Lu, Dingjie; Li, Shihao; Zeng, Xianting; Liu, Zhuangjian; Tee, Benjamin C.K.
• Other Names: Gao Wei guestEditor.; Yu Cunjiang guestEditor.
• Is Part Of: Advanced healthcare materials. Volume 10:Issue 17(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-17
• Subjects: finite element analysis -- health monitoring -- metal‐elastomer composites -- stretchable conductors -- wearables; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1002/adhm.202100221
• Languages: English
• ISSNs: 2192-2640

Abstract

Abstract: Stretchable electronics have advanced rapidly and many applications require high repeatability and robustness under various mechanical deformations. It has been described here that how a highly stretchable and reliable conductor composite made from helical copper wires and a soft elastomer, named eHelix, can provide mechanically robust and strain‐insensitive electronic conductivity for wearable devices. The reversibility of the mechanical behavior of the metal‐elastomer system has been studied using finite element modeling methods. Optimal design parameters of such helical metal‐elastomer structures are found. The scaling of multiple copper wires into such helical shapes to form a Multi‐eHelix system is further shown. With the same elastomer volume, Multi‐eHelix has more conductive paths and a higher current density than the single‐eHelix. Integrations of these eHelix stretchable conductors with fabrics showed wearable displays that can survive machine‐washes and hundreds of mechanical loading cycles. The integration of the eHelix developed by us with a wearable optical heart rate sensor enabled a wearable health monitoring system that can display measured heart rates on clothing. Furthermore, Multi‐eHelix conductors are used to connect flexible printed circuit boards and piezoresistive sensors on a tactile sensing glove for the emerging sensorized prosthetics. Abstract : A multi‐wire highly stretchable and mechanically robust conductor composite, named Multi‐eHelixes, is introduced to provide mechanical robustness and strain‐insensitive electronic conductivity. The stretchable conductor system is made from helical copper wires embedded within soft elastomers with optimal design parameters. These stretchable conductors can serve as reliable interconnects for various wearable healthcare devices and robotic applications.