A pressure sensor pad, also known as a bed pressure sensor, is a type of piezoelectric sensor. A piezoelectric sensor operates on the piezoelectric effect, which is a simple means by which changes in pressure, strain, force, temperature, or acceleration can be measured by a mechanical device by converting elements of these energies into an electrical charge and then measuring the charge. While many of the electrical charges measured by these systems are insignificant in an engineering sense, in a measurement sense they’re extremely important. A small charge that gives an accurate measurement, if not a perfect one as these sensors are poor devices for measuring static values, can be invaluable in a great range of scientific research.
However, the principles that make a piezoelectric sensor so good at measuring non-static values also enables them to react to changes in those values. Programs can be set to activate when the measurements of such a sensor detect a specific change in the measurements, ranging from the barely significant to the extreme shifts of heavy industry and research. Though these principles were discovered in 1880 by Pierre Curie, it was only in the 1950s that the principles became useful in the world of engineering and industry; initially only in the automotive manufacturing industry, but quickly spreading to the aerospace, nuclear energy, medical, and of some particular note, the field of consumer electronics. It’s considered a mature technology because it’s inherently reliable to the point where its use has spread far and wide in human society.
A pressure sensor pad exploits the piezoelectric principle to detect pressure on the pad. The measuring systems react to a certain amount of pressure on the pad, programmed into the electronics when the device is manufactured, though sometimes changeable via specific programs in the device. Pads of this variety are used for a number of applications. Touch pads and touch screens on consumer electronics are the most visible applications of these pads in modern life, particularly with the advent of smartphones and tablet computers. The sensors in the screen detect and trace changes in the pressure on the screen. From there, the programs in the pads react to the changes in pressure, activating other programs when specific shifts in pressure are noticed.
There are, however, many other uses for these technologies. Digital scales, widely regarded as more accurate than older types of scales, use this technology to measure changes in pressure and convert it into a specific weight measurement. Home security systems have also found use for this technology, as the sensor pads can be used to detect shifts in pressure on them and sound off an alarm if a specific shift in pressure is detected, such as damage to a window or a human-sized weight in an area.