Fig. 2: Structures and operating principles of the sweat VIA sensor and event-driven wireless monitoring of epidermal perspiration.
From: An epifluidic electronic patch with spiking sweat clearance for event-driven perspiration monitoring
Schematic diagrams of a the structures and operating principles of the sweat VIA sensor and b its equivalent circuit. c Example of a spike admittance curve produced by the sweat VIA sensor during the collection and clearance of sweat. d Schematic of the sweat rate versus spike frequency and sweat conductivity versus peak admittance of the spike signal. e The sweat VIA-based epifluidic wireless patch that wirelessly transmits measured data to a mobile phone via BLE. f Illustration of spiking-event-driven data transmission containing key information about sweat rate and ionic conductivity. The spike frequency and amplitude encode the sweat rate and ionic conductivity, respectively, with the spiking-event-driven readout requiring many fewer wireless data transmissions than a continuous readout.
