An epifluidic electronic patch with spiking sweat clearance for event-driven perspiration monitoring

• Published in: Nature communications 2022-11, Vol.13 (1), p.6705-12, Article 6705
• Main Authors: Kim, Sangha, Park, Seongjin, Choi, Jina, Hwang, Wonseop, Kim, Sunho, Choi, In-Suk, Yi, Hyunjung, Kwak, Rhokyun
• Format: Article
• Language: English
• Subjects: 639/166/985; 639/301; 692/700; 9/10; Biosensing Techniques; Clearances; Data processing; Data transmission; Edge computing; Electrodes; Electronics; Energy; Energy efficiency; External stimuli; Firing pattern; Humanities and Social Sciences; Information processing; Ion currents; Ions - analysis; Monitoring; Monitoring, Physiologic; multidisciplinary; Neurogenesis; Neurons; Perspiration; Science; Science (multidisciplinary); Sensory neurons; Signal processing; Skin; Spiking; Stimuli; Sweat; Sweat - chemistry; Sweating
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-34442-y

Sensory neurons generate spike patterns upon receiving external stimuli and encode key information to the spike patterns, enabling energy-efficient external information processing. Herein, we report an epifluidic electronic patch with spiking sweat clearance using a sensor containing a vertical sweat-collecting channel for event-driven, energy-efficient, long-term wireless monitoring of epidermal perspiration dynamics. Our sweat sensor contains nanomesh electrodes on its inner wall of the channel and unique sweat-clearing structures. During perspiration, repeated filling and abrupt emptying of the vertical sweat-collecting channel generate electrical spike patterns with the sweat rate and ionic conductivity proportional to the spike frequency and amplitude over a wide dynamic range and long time (> 8 h). With such ‘spiking’ sweat clearance and corresponding electronic spike patterns, the epifluidic wireless patch successfully decodes epidermal perspiration dynamics in an event-driven manner at different skin locations during exercise, consuming less than 0.6% of the energy required for continuous data transmission. Our patch could integrate various on-skin sensors and emerging edge computing technologies for energy-efficient, intelligent digital healthcare. Sensory neurons convert external stimuli into spike signals, enabling energy-efficient information processing. Here, Kwak et al. present a sensory neuron-inspired epifluidic wireless patch and demonstrate spike-based energy-efficient sweat monitoring.