How It Works:

The central element is a Piezo-ceramic bending element which is built up of several layers, rather like a bimetallic strip. When an electrical voltage is applied, this element bends a few hundredths of a millimetre. This bending allows air to enter the piezo valve through port 1 to port 2 (Fig. 2). In the unactuated mode, the air can flow from port 2 to port 3 (Fig. 1). Depending on the voltage applied, the lesser or greater bending of the element generates an analogue pressure signal at port 2. The piezo valve can therefore be used either as a switching valve or as a proportional valve. Optimized versions for either switching or proportional use are available.