ABSTRACT
This chapter presents various types of conventional pressure sensors which have applications for interface pressure measurement. These include conductive polymer sensors, semiconductor and metal strain gages, capacitive, and optoelectronic sensors. Most capacitive sensors are true pressure sensors, as are fiberoptic catheter sensors with pressure-sensitive membranes. Conductive polymer sensors are pressure sensors if the load is applied uniformly over the entire sensing area. All conventional pressure sensors depend on the deformation of a material to generate a pressure-dependent change. There are several key characteristics of deformable materials which influence the operating characteristics of the sensor. Most conventional pressure sensors have been designed to measure fluid pressures. However, human–seat interface pressure measurements are generally made by placing the sensor between two layers of compliant solid material such as silicone rubber. Most conductive polymer pressure sensors yield a decrease in resistance with increasing pressure.
