This EAGER project aims to realize the biodegradable epidermal devices by fabricating fully water-soluble zinc sensors on a water-soluble and ultra-smooth galactomannan substrate that is obtained from seeds with an environmentally-friendly aqueous extraction method. While there has been increasing attention to exploring biocompatible and biodegradable materials for implantable monitors and disposable epidermal sensors, the substrates are often associated with poor biodegradability, high surface roughness, lack of conformability, and expensive chemical synthesis approaches. In this project, various zinc sensors on the nature-derived galactomannan substrate will be fabricated, characterized, and benchmarked. The resulting disposable electronics can be programmed to dissolve in water, and further produce environmentally benign end-products, which can be used for alkaline soil amendments. Considering the numerous human health benefits such as reducing blood glucose and low-density lipoprotein cholesterol levels of the water-soluble galactomannan, the results from this study will also enable the future development of biomedical implants. Additionally, the research will be tightly coupled with a comprehensive educational program that will expose undergraduate and underrepresented students to interdisciplinary technologies through early engagement and research training on the design and fabrication of fully water-soluble sensors.
Significant efforts have been devoted to reducing the bending stiffness of epidermal devices to improve the contact quality at the device-skin interface and to yield high-quality sensing data. As the bending stiffness of the device is primarily affected by the modulus and thickness of each device layer, successful demonstrations include the use of low-modulus substrate or exploration of thin device structures. However, the materials are limited in the former, and low-cost fabrication is challenging in the latter. Additionally, non-water-soluble properties of both classes create electronic waste streams, posing environmental concerns. An innovative, fully water-soluble bioelectronic device is proposed in which zinc sensors are fabricated on the galactomannan substrate through a low-cost fabrication process. The objective of this project is to carry out a feasibility study that water-soluble bioelectronics on a skin-conforming galactomannan film can form a conformal contact with the hierarchically textured skin surface and reduce the contact impedance. Two research tasks are proposed to accomplish the feasibility study: (1) fabricating capacitive zinc electrodes and temperature sensors on the skin-conforming galactomannan films, and (2) characterizing water-soluble zinc sensors to benchmark their performance, particularly against motion artifacts. By following arbitrary skin deformations without mechanical failure, the new class of fully disposable, high-performance, and low-cost electronic devices can significantly improve the contact quality at the device-skin interface and reduce the susceptibility to motion artifacts.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
