New pressure sensor boasts enhanced sensitivity

Citation

(2001), "New pressure sensor boasts enhanced sensitivity", Sensor Review, Vol. 21 No. 3. https://doi.org/10.1108/sr.2001.08721cab.009

New pressure sensor boasts enhanced sensitivity

New pressure sensor boasts enhanced sensitivity

Keyword: Pressure sensors

A new pressure sensor boasts heightened sensitivity. It is pliant like the skin and sensitive enough to detect correctly even the lightest touch – enough to give robots just the sensitivity required to find employment in the health-care profession which looks to achieve rapid growth in the twenty-first century. Other potential applications include high-performance sensors for automotive and computer usage.

The new sensor weds the sensor technologies in Japan's Inaba Rubber Co. Ltd in Osaka City, central Japan, with the ceramic technologies of the Osaka University Institute of Science & Industry Research. The device is an example of a nanocomposite, that is a composite made by mixing different materials into silicone rubber melted in a crucible. (A micron is one-millionth of a metre; a nanometre, one-billionth.)

Silicon rubber is not conducive and the nanocomposite at rest will not allow an electric current to pass. The carbon particles do conduct electricity, however, so that when pressure is applied and the composite deforms and carbon particles come into contact with one another, they form a pathway for the flow of electricity.

This is the mechanism used by the pressure sensor to signal that it has touched or has been touched by something. The alumina particles help disperse the carbon particles more evenly throughout the silicone rubber, making the flow of current more stable and boosting the sensor's sensitivity. At the same time, the alumina helps preserve the flexibility and the elasticity of the rubber.

This is not the first time a pressure sensor has been developed by mixing conductive particles into rubber, but rubber tends to harden over time and undergo changes in its characteristics, making it difficult to produce reliable sensors.

Another problem is that the stiff rubber must be loosened up before it can be used so that it is not practical to incorporate the sensors on industrial output lines.

The new pressure sensor can detect contacts across a continuous range of forces, from a very light touch to strong pressure, so that when the pressure is relaxed, the device returns to its original shape. In addition, the sensor can be processed into both flat and rounded shapes.