University of Missouri-Columbia columbia, Missouri, United States
Introduction: Porous soft bioelectronics have recently attracted significant interest for their superior breathability, long-term biocompatibility, and other unique properties inaccessible in nonporous alternatives. Developing these electronics with customized functionalities is essential for meeting the diverse needs of precision human healthcare. However, the prevailing method for producing soft bioelectronics remains cleanroom-based nano/microfabrication, involving costly and complex processes such as e-beam or photolithography, vacuum deposition, etching, and transfer printing, which lack design flexibility. We have explored innovative biomanufacturing methods, including laser scribing and solution printing, to enable high-throughput, cost-effective, customizable production of multimodal porous soft bioelectronics. For example, we achieved direct laser scribing of metallic conductive molybdenum dioxide on porous elastomers, which can serve as the basis for constructing a variety of biosensors. Additionally, we have developed multifunctional cellulose nanofibril interfaces that enhance printing quality, enable strain resilience, and offer microfluidics in porous bioelectronics. The exemplary device examples include those that can collect multiple desired biosignals from human bodies and surrounding environments for nutrition management, alcoholism studies, and metabolic status monitoring.
Materials and
Methods: Styrene-ethylene-butylene-styrene (SEBS) was utilized to create porous substrates through phase separation. A CO2 laser beam scribed molybdenum chloride precursor sprayed onto porous SEBS, forming highly conductive molybdenum dioxide with customized patterns for bioelectronics fabrication. Additive manufacturing of high-quality bioelectronics was achieved by extruding and inkjet printing bifunctional inks of silver nanowires and poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate) onto a cellulose nanofibril interfaced porous SEBS using a commercial solution printer.
Results, Conclusions, and Discussions: Using laser-based fabrication, we have developed a Janus multimodal porous bioelectronics device capable of collecting electrophysiological signals, temperature, and sweat biomarkers from human skin, along with alcohol and ammonia concentrations from breath, and ultraviolet density and humidity from the surrounding environment. This device can track caffeine, uric acid, and glucose levels post-meal, showcasing its utility in precision nutrition management. It also monitors changes in the slow alpha area, breath alcohol concentration, heart rate, and heart rate variability following alcohol intake, highlighting its potential in alcoholism research. Additionally, through solution printing, we developed a multilayer porous bioelectronic device on cellulose nanofibril-interfaced porous elastomer substrates. This device features electrophysiological sensors, glucose sensors, β-hydroxybutyrate sensors, and microfluidic channels, facilitating continuous sweat collection and analysis for glucose and β-hydroxybutyrate concentrations, alongside electrocardiogram data capture from the upper arm to determine heart rate, heart rate variability, and energy expenditure. By tracking glucose and β-hydroxybutyrate, key biomarkers of carbohydrate and ketone metabolism respectively, the device provides crucial metabolic insights. Incorporating energy expenditure data from electrocardiograms, it offers invaluable guidance for individuals managing their metabolic health.
