Polysomnographic Observation Using Triboelectric Pressure Sensor Composed of Polymer-Pairs Having Coarse Surface

In this research, the triboelectric sensors are fabricated using a facile stacking of nonwoven thermoplastic polyurethane (TPU nw ) and as-spun thermoplastic polyurethane nanofiber web (TPU nf ) with nonwoven polypropylene (PP), and as-cast silicone elastomer. The triboelectric output voltage of the sensor is examined by applying a periodic dynamic mechanical load ranging from 0.1 to1 kgf at a constant frequency of 1 Hz. Among the combinations, the TPU nw (3.3 V) gives almost 4 times higher peak-to-peak voltage ( V p-p ) than TPU nf (0.9 V) with a given nonwoven PP fabric. Similarly, with as-cast rough silicone elastomer, the TPU nw (10.1 V) gives 20 % increase of V p-p compared with TPU nf (7.9 V). From the above results, we can conclude that the nonwoven TPU generates larger triboelectric voltages than the electrospun TPU nanoweb and it may be due to the higher roughness of the former than the latter. Compared to nonwoven PP, the rough surface silicone elastomer (Si) gives almost 3 times larger V p-p with TPU nw . The combinative effect of triboelectric polarity and surface roughness plays a significant role in the enhancement of V p-p in Si combination rather than PP. In addition to this, the potential applications of physiological vital signs (respiration and heartbeat rate) and movements of a human are examined during polysomnographic (PSG) measurement with TPU nw -PP senor using a BIOPAC MP150 data acquisition system in conjunction with a signal conditioner. During PSG measurement, the heartbeat and respiration at four different positions are successfully measured. Apneic events and disruptive body movements were also easily observed.