SBIR Phase I: Spatially-heterogeneous modulus substrates for stretchable electronics fabrication

This Small Business Innovation Research Phase I project will assess the commercial viability of a new substrate material specifically designed for reducing the manufacturing complexity of stretchable electronics. Currently a $1.6 million market, stretchable electronics are expected to grow at a cumulative annual growth rate of 101.3% to reach $412 million in sales by 2023 due to the surge in wearable technologies, structural health monitoring devices, and medical diagnostic tools. In part, the current market size for stretchable electronics is limited by the immature manufacturing tools and techniques required, such as transfer- and nano-printing. The research and development funded by the Phase I SBIR could lead to a drastic reduction in manufacturing complexity, allowing stretchable electronic devices to be manufactured using current industry standard photolithographic techniques. The intellectual merit of this project lies in the ability to create electronic substrate materials with intrinsic stiffness differences (those without laminated layers, patterned fillers, etc.) that are defined using standard lithography techniques. Specifically, these substrates can be spatially segregated into regions of low Young's modulus (the soft matrix) and regions of high Young's modulus (the stiff islands) with a difference in modulus between these two regions reaching ratios of 1000:1 (stiff:soft). In the initial work, demonstrations of these spatially-heterogeneous modulus substrates show that spatial resolution can be achieved at the millimeter scale, and can introduce localized strain across the substrate as a function of the patterned stiff regions. The objectives for this project are focused on (a) engineering an optimal starting substrate material with the desired properties for the soft region and (b) demonstrating microfabrication of micropatterned thin-film components (feature sizes < 20 microns) of stiff regions introduced into the material. This Phase I grant will culminate in prototype thin-film electronic components which maintain electrical performance at high global strains, while also showing the capacity of the substrate materials to withstand the harsh thermal and chemical conditions observed during microfabrication.