Respiratory monitoring plays a pivotal role in health assess-ment and provides an important application prospect for flexible humidity sensors.However,traditional humidity sensors suffer from a trade-off between deformability,sensitivity,and transparency,and thus the development of high-performance,stretchable,and low-cost humidity sensors is urgently needed as wearable electronics.Here,ultrasensitive,highly deformable,and transparent humidity sensors are fabricated based on cost-effective polyacrylamide-based double network hydrogels.Concomitantly,a general method for preparing hydrogel films with controllable thickness is proposed to boost the sensitivity of hydrogel-based sensors due to the extensively increased specific surface area,which can be applied to different polymer networks and facilitate the development of flexible integrated electronics.In addition,sustainable tapioca rich in hydrophilic polar groups is introduced for the first time as a second cross-linked network,exhibiting excellent water adsorption capacity.Through the synergistic optimization of structure and composition,the obtained hydrogel film exhibits an ultrahigh sensitivity of 13,462.1％/％RH,which is unprecedented.Moreover,the hydrogel film-based sensor exhibits excellent repeatability and the ability to work normally under stretching with even enhanced sensitivity.As a proof of concept,we integrate the stretchable sensor with a specially designed wireless circuit and mask to fabricate a wireless respiratory interruption detection system with Bluetooth transmission,enabling real-time monitoring of human health status.This work provides a general strategy to construct high-performance,stretchable,and miniaturized hydrogel-based sensors as next-generation wearable devices for real-time monitoring of various physiological signals.

Yuning Liang;Qiongling Ding;Hao Wang;Zixuan Wu;Jianye Li;Zhenyi Li;Kai Tao;Xuchun Gui;Jin Wu

State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology,School of Electronics and Information Technology,Sun Yat-Sen University,Guangzhou 510275,People's Republic of China;Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace,Northwestern Polytechnical University,Xi'an 710072,People's Republic of China Acknowledgements J.W.acknowledges financial supports from the National Natural Science Foundation of China(61801525),the Guangdong Basic and Applied Basic Research Foundation(2020A1515010693)and the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(22lgqb17).

纳微快报（英文）

[1]Yuning Liang;Qiongling Ding;Hao Wang;Zixuan Wu;Jianye Li;Zhenyi Li;Kai Tao;Xuchun Gui;Jin Wu-.Humidity Sensing of Stretchable and Transparent Hydrogel Films for Wireless Respiration Monitoring)[J].纳微快报（英文）,2022(11):218-236

Respiration,Concomitantly,tapioca

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