Evaluation of pressure sensors based on piezoresistive films for integration in smart medical textiles

n present research, pressure sensors based on piezoresistive films for integration in smart medical textiles are evaluated using rigid electrodes forming rigid experimental pressure sensors. A systematic study was carried out to investigate the effect of sensing area and number of layers of piezoresistive films on experimental pressure sensor's performance parameters such as pressure sensitivity, hysteresis, and accuracy of output. At 10 kPa pressure, these experimental pressure sensors with a sensing area of 100 mm2 demonstrated pressure sensitivity of 0.05 kPa-1. The pressure sensitivity of sensors increased with an increase in sensing area and with the number of layers of the piezoresistive film. Hysteresis remained in a range of 23% to 25% and demonstrated negligible variations with change in sensing area from 100 mm2 to 900 mm2. The accuracy of all the sensors was found to be above 80%, however no pronounced corelation between the sensing area and the number of layers of the piezoresistive film was observed. It was found that the piezoresistive sensing film can be sucessfully used to fabricate a pressure sensor operating in low-pressure range below 50 kPa.