Piezoelectrically actuated ejector using PMN-PT single crystal

A piezoelectric fluid ejector has been fabricated using a Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (PMN-PT) single crystal ring. The design of the ejector is based on resonant modes of a flextensional transducer that is constructed by bonding a PMN-PT ring to a thin circular metal membrane with a small orifice at the centre. The fluid is placed, at atmospheric pressure, behind one face of the membrane. By applying an appropriate voltage to the PMN-PT ring, a continuous or drop-on-demand ejection of ink or water can be achieved. With the PMN-PT single crystal as the driving element, the ejector has a very high axial displacement and can be driven at a low voltage. The performance of the PMN-PT single crystal ejector has been compared with the ejector fabricated using PZT ceramics and is formed to have better performance.