Centre for Interdisciplinary Programs, Integrated Sensor Systems, Indian Institute of Technology-Hyderabad, Kandi, Sangareddy, India.
Department of Electrical Engineering, Indian Institute of Technology-Hyderabad, Kandi, Sangareddy, India.
Mikrochim Acta. 2024 Aug 6;191(9):514. doi: 10.1007/s00604-024-06595-8.
A cleanroom free optimized fabrication of a low-cost facile tungsten diselenide (WSe) combined with chitosan-based hydrogel device is reported for multifunctional applications including tactile sensing, pulse rate monitoring, respiratory rate monitoring, human body movements detection, and human electrophysiological signal detection. Chitosan being a natural biodegradable, non-toxic compound serves as a substrate to the semiconducting WSe electrode which is synthesized using a single step hydrothermal technique. Elaborate characterization studies are performed to confirm the morphological, structural, and electrical properties of the fabricated chitosan/WSe device. Chitosan/WSe sensor with copper contacts on each side is put directly on skin to capture human body motions. The resistivity of the sample was calculated as 26 kΩ m. The device behaves as an ultrasensitive pressure sensor for tactile and arterial pulse sensing with response time of 0.9 s and sensitivity of around 0.02 kPa. It is also capable for strain sensing with a gauge factor of 54 which is significantly higher than similar other reported electrodes. The human body movements sensing can be attributed to the piezoresistive character of WSe that originates from its non-centrosymmetric structure. Further, the sensor is employed for monitoring respiratory rate which measures to 13 counts/min for healthy individual and electrophysiological signals like ECG and EOG which can be used later for detecting numerous pathological conditions in humans. Electrophysiological signal sensing is carried out using a bio-signal amplifier (Bio-Amp EXG Pill) connected to Arduino. The skin-friendly, low toxic WSe/chitosan dry electrodes pave the way for replacing wet electrodes and find numerous applications in personalized healthcare.
一种无尘室优化的低成本简易二硒化钨（WSe）与壳聚糖基水凝胶器件的制备方法，可用于包括触觉传感、脉搏率监测、呼吸率监测、人体运动检测和人体生理电信号检测在内的多功能应用。壳聚糖作为一种天然可生物降解、无毒的化合物，可用作半导体 WSe 电极的基底，该电极是使用一步水热技术合成的。进行了详细的特性研究，以确认所制备的壳聚糖/WSe 器件的形态、结构和电学性能。在每一侧都有铜接触的壳聚糖/WSe 传感器直接放在皮肤上，以捕捉人体运动。样品的电阻率计算为 26 kΩ m。该器件具有超灵敏的压力传感器特性，可用于触觉和动脉脉搏感测，其响应时间为 0.9 s，灵敏度约为 0.02 kPa。它还能够进行应变感测，其应变系数为 54，明显高于类似的其他报道的电极。人体运动的感应归因于 WSe 的压阻特性，这源于其非中心对称结构。此外，该传感器还可用于监测呼吸率，对于健康个体的呼吸率测量为 13 次/分钟，还可以监测心电图（ECG）和眼电图（EOG）等生理电信号，这些信号可用于以后检测人类的多种病理状况。生理电信号的感应是通过与 Arduino 相连的生物信号放大器（Bio-Amp EXG Pill）进行的。这种对皮肤友好、低毒性的 WSe/壳聚糖干电极为替代湿电极铺平了道路，并在个性化医疗保健中找到了众多应用。
