2, Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, Maryland, United States
Flexible and ultrathin substrates supporting microelectronic components have the potential to spur the development of pervasive healthcare and the internet of things by providing sensors and bioelectronics that can provide seamless and imperceptible integration. We will describe our ongoing work to develop sensing electronics on microns-thin bacterial nanocellulose for human monitoring applications. The porosity and hydrophobicity of nanocellulose sheets offer advantages that typical plastics cannot provide, such wicking of analytes and absorption of inks. We have developed a printing method to form nanocellulose printed circuit boards (PCBs), and created a simple low temperature soldering process to form circuit structures using standard surface-mount components on our nanocellulose PCBs. This has been used to create nanocellulose decals that measure human body temperature and perform pulse oximetry. We have also developed self-powered electronics for sensing of bioanalytes, such as glucose. For all applications, the fabrication processes are solution-based and requires only ambient processing, and therefore simple, potentially low-cost, and can be aimed for a wide range of applications.