TABLE 50.1 Electrostrictive and Dielectric Data for Some Common Actuator materials Dielectric M3×10m2/V2 Constant K Ref b(MgusNbys)O, (PMN) 15.04 9140 (Pb1:a2x)(zr1T1o3(PLzr1165/35) Landolt- Bornstein BatiO, (poled) Nomura and Uchino, 1983 Pb 5.61×10-2 PVDF/TrFE copolymer 12 Elhami et al, 1995 At room temper low frequency (<100 Hz)and low magnitude electric fields(<0. 1 MV/m) d33 pm/V Electric Field, MV/m FIGURE 50.4 Induced piezoelectric coefficients d, and-d,i as a function of applied biasing field for ceramic PMN, 18C. 50.4 Applications The advantages that electrostrictors have over other actuator materials include low hysteresis of the strain-field response, no remanent strain(walk off), reduced aging and creep effects, a high response speed(<10 ms), and strain values(>0.03%)achievable at realizable electric fields. Displacement ranges of several tens of micre may be achieved with +oolu reproducibility. Most actuator applications of electrostrictors as servotransducers and micropositioning devices take advantage of these characteristics. Mechanical applications range from stacked actuators through inchworms, microangle adjusting devices, and oil pressure servovalves. Multilayer actuators produce large displacements and high forces at low drive voltages. The linear change in capacitance with applied stress of an electrostrictor can be used as a capacitive stress gauge [Sundar and Newnham, 1992]. Electrostrictors may also be used as used in field-tunable piezo electric transducers. Recently, electrostrictive materials have been integrated into ultrasonic motors and novel flextensional transducers lectrostrictors have also been integrated into"smart "optical systems such as bistable optical devices, interferometric dilatometers, and deformable mirrors. Electrostrictive correction of optical aberrations is a ignificant tool in active optics. Electrostrictors also find applications in"very smart" systems such as sen- or-actuator active vibration-suppression elements. A shape memory effect arising from inverse hysteretic behavior and electrostriction in PZT family antiferroelectrics is also of interest. A recent survey [Uchino, 1993] predicts that the market share of piezoelectric and electrostrictive transducers is expected to increase to more than $10 billion by 1998 c 2000 by CRC Press LLC© 2000 by CRC Press LLC 50.4 Applications The advantages that electrostrictors have over other actuator materials include low hysteresis of the strain-field response, no remanent strain (walk off), reduced aging and creep effects, a high response speed (<10 ms), and strain values (>0.03%) achievable at realizable electric fields. Displacement ranges of several tens of microns may be achieved with ±0.01m reproducibility. Most actuator applications of electrostrictors as servotransducers and micropositioning devices take advantage of these characteristics. Mechanical applications range from stacked actuators through inchworms, microangle adjusting devices, and oil pressure servovalves. Multilayer actuators produce large displacements and high forces at low drive voltages. The linear change in capacitance with applied stress of an electrostrictor can be used as a capacitive stress gauge [Sundar and Newnham, 1992]. Electrostrictors may also be used as used in field-tunable piezo￾electric transducers. Recently, electrostrictive materials have been integrated into ultrasonic motors and novel flextensional transducers. Electrostrictors have also been integrated into “smart” optical systems such as bistable optical devices, interferometric dilatometers, and deformable mirrors. Electrostrictive correction of optical aberrations is a significant tool in active optics. Electrostrictors also find applications in “very smart” systems such as sen￾sor–actuator active vibration-suppression elements. A shape memory effect arising from inverse hysteretic behavior and electrostriction in PZT family antiferroelectrics is also of interest. A recent survey [Uchino, 1993] predicts that the market share of piezoelectric and electrostrictive transducers is expected to increase to more than $10 billion by 1998. TABLE 50.1 Electrostrictive and Dielectric Data for Some Common Actuator Materialsa Composition M33 ¥ 10–17 m2 /V2 Dielectric Constant K Ref. Pb(Mg1/3Nb2/3)O3 (PMN) 15.04 9140 Nomura and Uchino, 1983 (Pb1-xLa2x/3)(Zr1-yTiy)O3 (PLZT 11/65/35) 1.52 5250 Landolt-Bornstein BaTiO3 (poled) 1.41 1900 Nomura and Uchino, 1983 PbTiO3 1.65 1960 Landolt-Bornstein SrTiO3 5.61 ¥ 10–2 247 Landolt-Bornstein PVDF/TrFE copolymer 43 12 Elhami et al., 1995 a At room temperature, low frequency (<100 Hz) and low magnitude electric fields (<0.1 MV/m). FIGURE 50.4 Induced piezoelectric coefficients d33 and –d31 as a function of applied biasing field for ceramic PMN, 18°C