Micro Piezo Actuators - CEDRAT TECHNOLOGIES - #1

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CEDRAT GROUPE www.cedrat.com Micro Piezo Actuators Obtaining an integratable, compatible, low cost mechanical energy source providing a sufficient quantity of easily accessible energy within a miniaturised system has been an ongoing challenge for decades. The urgency and interests of such systems will continue to increase with the development of portable microsystems. The conventional approach to mechanical actuation is based on electromagnetic machines. This option is very efficient but difficult to integrate at microscopic scales. Actuation making use of piezo-electric elements became widespread starting from the 1990s, and this is an important step forward for microsystems since it is very easy to integrate, it is relatively powerful and easy to use. Obviously there is still a real actuator need to be satisfied for integrated and high power actuation. Today the trend which is the extreme system miniaturisation and complexification leads to new technological and material challenges. Objective In the frame of the MUFLY FP6 EC project, which targets a 20g micro-helicopter, new miniature piezo actuators and driving electronic of less than 0.2g are required. In that regard, ultra-light weight actuators with a high power to mass ratio have been developed. In addition a miniature driver for piezo-electric actuators addresses the issues of compact micro embedded components. Description These new miniature actuators are based on the concept of the standard Amplified Piezo Actuators. The APA® utilises the metallic shell to amplified motions from the piezo stack and to pre-stress it (Fig.1). This pre-stress is required to withstand large external vibrations. Micro Amplified Piezo Actuator: APAìXS The APA ìXS (Fig.2) is the smallest actuator of the range of CEDRAT TECHNOLOGIES’ APA®. Since they are based on tiny MLA, special care was provided in the design. They offer the following features: • Ultra light weight, • Small and Compact, • Great Stroke, • High bandwidth, • Robust design, • Low cost. Micro Tilt: TiltìXS The new micro tilt (Fig.3) of CEDRAT TECHNOLOGIES, so called Tilt ìXS, is based on two APA ìXS’s and a level arm realised in a monolithic part. Thickness, hinge Length and the pivot point pitch are optimised to allow the maximum deflection amplification on the arm tip. Indeed, the level of stroke amplification in relation to the APA ìXS is up to 6. Fig.1: APA® FEM Deformed structure. Fig.2: View of the APA ìXS. Fig.3: View of the Tilt ìXS.