Paper-based microfluidic chip for sweat volume, ECG and EMG monitoring

With the development of wearable devices, the application of non-invasive wearable devices to monitor sweat in real time is the most important for human health. Here, a paper-based microfluidic chip for monitoring of sweat loss during exercise is proposed. Highly absorbent rice paper is selected as the paper-based material, and the capillary action of the paper base is used to actively adsorb sweat, and it can be used repeatedly. As the electrode material, the conductive cloth has good tensile properties and bending resistance, which ensures that the change of resistance is caused by the amount of sweat entering. Other materials of the chip are highly hydrophobic, ensuring that all sweat will be absorbed by the paper base. The sweat volume monitored by the microfluidic chip in real time is 0.5μl-225μl. Compared with rigid electrodes and wet electrodes, the application of flexible electrodes allows the chip to fit well with the skin, the ECG waveform is clearer and has greater amplitude, and the EMG is smoother and has a greater signal-to-noise ratio.