Stretchable electronics for wearable and high-current applications

Abstract

Advances in the development of novel materials and fabrication processes are resulting in an increased number of flexible and stretchable electronics applications. This evolving technology enables new devices that are not readily fabricated using traditional silicon processes, and has the potential to transform many industries, including personalized healthcare, consumer electronics, and communication. Fabrication of stretchable devices is typically achieved through the use of stretchable polymer-based conductors, or more rigid conductors, such as metals, with patterned geometries that can accommodate stretching. Although the application space for stretchable electronics is extensive, the practicality of these devices can be severely limited by power consumption and cost. Moreover, strict process flows can impede innovation that would otherwise enable new applications. In an effort to overcome these impediments, we present two modified approaches and applications based on a newly developed process for stretchable and flexible electronics fabrication. This includes the development of a metallization pattern stamping process allowing for 1) stretchable interconnects to be directly integrated with stretchable/wearable fabrics, and 2) a process variation enabling aligned multi-layer devices with integrated ferromagnetic nanocomposite polymer components enabling a fully-flexible electromagnetic microactuator for large-magnitude magnetic field generation. The wearable interconnects are measured, showing high conductivity, and can accommodate over 20% strain before experiencing conductive failure. The electromagnetic actuators have been fabricated and initial measurements show well-aligned, highly conductive, isolated metal layers. These two applications demonstrate the versatility of the newly developed process and suggest potential for its furthered use in stretchable electronics and MEMS applications.

A Low-Cost, Micropattern Transfer Process for Thick-Film Metallization of PDMS

“…47 Other experiments demonstrating the application of this process to wearable fabrics and multi-layer devices are also presented previously. 44 This section contains the experimental procedure used to acquire the measurement data, while the Results and analysis section contains the measurement results and analysis.…”

“…In addition, the unique infrared (IR)-assisted transfer from a sacrificial conductive paint seed layer has been demonstrated to make the metallization process adaptable to a variety of substrates and applications, such as fabrics and aligned multi-layer devices. 44 The first iteration of this process and the corresponding initial results related to feature size, surface roughness, film thickness, and conductivity are presented in a previous study. 45 The previous study focuses on the evolution of the metallization layer through each processing step, and provides only preliminary results with limited or no statistical assessment for each measurement.…”