SILVER NANOWIRE-BASED WEARABLE DEVICES FOR PHYSIOLOGICAL SENSING

Abstract

Stretchable electronics are a technology that has allowed for the creation of new wearable devices for the non-invasive collection of physiological data for healthcare monitoring. Nanomaterial enabled stretchable electronics are one class of stretchable electronic materials. These are composite materials consisting of a stretchable a flexible matrix, usually a polymer, and a conductive nanoparticle, like metallic nanowires, graphene, or carbon nanotubes. Challenges exist when it comes to integrating wearable devices based on stretchable electronics with existing rigid technology, with the manufacturing considerations needed to repeatably and reliably couple the flexible matrix with the conductive nanomaterial, and with taking steps to optimize designs to improve the sensitivity of devices. In this work, contributions are made towards addressing these challenges that exist in the field of stretchable electronics enabled wearable devices. Specifically, the following contributions are made. 1) An electrocardiogram sensor that is self-adhering and integrates with current technologies is demonstrated. 2) A mould-based method for repeatably and reliably patterning silver nanowires (AgNWs) on polydimethylsiloxane (PDMS) is demonstrated in 2-dimensions. 3) The mould-based technique is extended to allow for patterning AgNWs on curved surfaces, in addition to flat 2-dimensional surfaces. 4) A novel design for a wearable contact lens that can detect intraocular pressure for the purpose of glaucoma detection is demonstrated. 5) The sensor design is improved by changing from a traditional contact lens to a ring-shaped contact lens. 6) The quantification of the changes to transparency and Young’s modulus of PDMS when a laser cutter is used on the material.