Actuation performance analysis of piezo-composite unimorph actuator with d33 actuation mechanism of piezo-electric ceramic layer

Abstract

The performance improvement of the LIPCA (Lightweight Piezo-Composite curved Actuator) is investigated in this paper. The LIPCA is known as the best layered piezo-composite unimorph actuator because of not only high performance but also its flexible analytical design model and simple fabrication technique. Besides, originated from efforts to develop highly induced-strain piezoelectric ceramic, the IDEAL (Inter-Digitated Electrode Actuation Layer) have shown to be a potential candidate in unimorph or bimorph actuator designs. In a latest model of IDEAL designs, the inter-digitated electrodes (IDEs) had been proposed to be embedded directly into the piezoelectric ceramic wafer. Hence, the resulting stacked-type transducer is able to have full d33 actuation mechanism which can produce almost twice larger strain than that produced by the conventional d31 actuation mechanism. Therefore, by replacing the original actuation layer with IDEAL in the lay-up structure of the conventional LIPCA design, one can expect improvement to the performance of the actuator, e.g., gaining higher of out-of-plane actuation displacement. The modified design of LIPCA had been investigated considering mechanical properties of an inhomogeneous IDEAL. As the result, an IDEAL fabricated with low-elastic-modulus IDEs have shown to give considerably improvement on actuation performance of the LIPCA. Following that sense, a new homogenization model applied to the embedded IDEAL is proposed and able to convince the previously obtained result.