Knitted self-powered sensing textiles for machine learning-assisted sitting posture monitoring and correction

With increasing work pressure in modern society,prolonged sedentary positions with poor sitting postures can cause physical and psychological problems,including obesity,muscular disorders,and myopia.In this paper,we present a self-powered sitting position monitoring vest(SPMV)based on triboelectric nanogenerators(TENGs)to achieve accurate real-time posture recognition through an integrated machine learning algorithm.The SPMV achieves high sensitivity(0.16 mV/Pa),favorable stretchability(10%),good stability(12,000 cycles),and machine washability(10 h)by employing knitted double threads interlaced with conductive fiber and nylon yarn.Utilizing a knitted structure and sensor arrays that are stitched into different parts of the clothing,the SPMV offers a non-invasive method of recognizing different sitting postures,providing feedback,and warning users while enhancing long-term wearing comfortability.It achieves a posture recognition accuracy of 96.6%using the random forest classifier,which is higher than the logistic regression(95.5%)and decision tree(94.3%)classifiers.The TENG-based SPMV offers a reliable solution in the healthcare system for non-invasive and long-term monitoring,promoting the development of triboelectric-based wearable electronics.

Flexible and wearable BaTiO_(3)/polyacrylonitrile-based piezoelectric sensor for human posture monitoring

Tactile sensors are essential components of wearable electronic devices,but there are still various problems in terms of energy supply,flexibility and skin adaptability.In this paper,we report a self-powered flexible tactile sensor(FTS)mainly composed of a BaTiO_(3)/polyacrylonitrile/Ecoflex(BTO/PAN/Ecoflex)composite film,which can be used for dynamically monitoring human plantar pressure,posture and other physiological and motion parameters.Combining the synergistic piezoelectric properties of PAN and BTO,the output voltage/current of the BTO/PAN/Ecoflex composite film is 4.5/5.8 times that of the BTO/Ecoflex composite film,with maximum instantaneous power that can reach up to 3.375μW.Under the action of external pressure stress,the FTS can reach a normalized voltage sensitivity and voltage linearity of 0.54 V/N and 0.98,respectively.Furthermore,a human-machine interaction test system is built,which can display the stress changes of human body monitoring parts in real time according to voltage changes and different color assignments.The developed human-machine interaction test system provides a new idea for the diagnosis of flatfoot and other medical diseases.Hence,this work proposes new FTSs that use a BTO/PAN/Ecoflex composite film with high sensitivity and great output performance,thus exhibiting immense potential application prospects in medical research,personalized recognition and human-machine interaction.