Fully Integrated, Stretchable, Wireless Skin‐Conformal Bioelectronics for Continuous Stress Monitoring in Daily Life

Abstract

Stress is one of the main causes that increase the risk of serious health problems. Recent wearable devices have been used to monitor stress levels via electrodermal activities on the skin. Although many biosensors provide adequate sensing performance, they still rely on uncomfortable, partially flexible systems with rigid electronics. These devices are mounted on either fingers or palms, which hinders a continuous signal monitoring. A fully‐integrated, stretchable, wireless skin‐conformal bioelectronic (referred to as “SKINTRONICS”) is introduced here that integrates soft, multi‐layered, nanomembrane sensors and electronics for continuous and portable stress monitoring in daily life. The all‐in‐one SKINTRONICS is ultrathin, highly soft, and lightweight, which overall offers an ergonomic and conformal lamination on the skin. Stretchable nanomembrane electrodes and a digital temperature sensor enable highly sensitive monitoring of galvanic skin response (GSR) and temperature. A set of comprehensive signal processing, computational modeling, and experimental study provides key aspects of device design, fabrication, and optimal placing location. Simultaneous comparison with two commercial stress monitors captures the enhanced performance of SKINTRONICS in long‐term wearability, minimal noise, and skin compatibility. In vivo demonstration of continuous stress monitoring in daily life reveals the unique capability of the soft device as a real‐world applicable stress monitor.

Stress Monitoring and Recent Advancements in Wearable Biosensors

“…This flexible hybrid electronic device is skin-conformant, accurate, sensitive, and allows for the real-time capture of stress related data. As seen in Figure 2D , SKINTRONICS is a multilayered device with a wear time of up to 7 h. The group was able to achieve galvanic skin response results comparable to those of commercially available devices with the same purpose, but with the added advantage of offering long-term, hands-free use ( Kim et al, 2020 ). Other skin-interfaced sensing platforms are in development, indicating a trend toward flexible sensing ( Sekar et al, 2019 ; Kim et al, 2020 ).…”

“…(C) printed graphene-based wireless cortisol sensor, reprinted with permission from Torrente-Rodríguez et al, copyright 2020 by Elsevier ( Torrente-Rodríguez et al, 2020 ). (D) galvanic skin response sensor SKINTRONICS ( Kim et al, 2020 ) reprinted via Creative Commons Attribution 4.0.…”

“…The MIP was found to be reversible, reproducible, and reusable, effectively overcoming the shortcomings that antibody-antigen devices possess, while also being flexible and wearable due to development on a soft styrene-ethylene-butylene-styrene elastomer, as shown in Figure 2C ; Parlak et al (2018) . Apart from cortisol sensing, Kim et al (2020) reported a device they term “SKINTRONICS” which utilizes electrodermal sensing of galvanic skin response paired with temperature recording to determine stress levels. This flexible hybrid electronic device is skin-conformant, accurate, sensitive, and allows for the real-time capture of stress related data.…”

Soft Wireless Bioelectronics and Differential Electrodermal Activity for Home Sleep Monitoring

“…The fabrication of a soft electronic circuit followed the customized strategy reported in our prior works that used microfabrication and material transfer printing [ 30 , 31 ]. The overall process includes the following: polydimethylsiloxane/polyimide (PDMS/PI) was spin-coated on a 4-inch Si wafer.…”

NFC-Based Wearable Optoelectronics Working with Smartphone Application for Untact Healthcare

“…However, with the growing interest, the increase in medical expenses has affected as an economic burden for both individuals and governments [ 5 , 6 , 7 , 8 ]. Accordingly, wearable healthcare devices have been researched and developed with various bio-signal sensing (e.g., physical [ 9 , 10 , 11 ], thermal [ 12 , 13 , 14 ], and cardiovascular [ 15 , 16 , 17 , 18 ] signals). Among them, the thermal and cardiovascular signals can be an important indicator for diagnosing patient conditions [ 19 ].…”