Surface Correction Control Based on Plasticized Multilayer P(VDF‐TrFE‐CFE) Actuator—Live Mirror

Abstract

high-bandwidth communication, civil space surveillance technologies, wireless optical communication systems (UV and free-space systems), hyper-aperture multimirror structures, geoengineering (space mirror), and astronomical systems. [1,2] In particular the light-gathering power of an optical telescope, its "light grasp" or aperture gain, is one of the most important features of a telescope, [3] which requires very precise glass mirror technology.Recently, we have proposed a "World's Largest Telescope" for achieving highcontrast observations that could use this technology. [4][5][6] Such an optical system will be limited by the cost and manufacturability of large mirrors. The work described here, optics fabricated from an optimized electroactive polymer (EAP), could enable optics like these. The new approach will extend conventional active mirror technologies to larger smooth optical surfaces, without abrasive polishing. This means it will be possible to create precisely shaped low scattered light mirrors-suitable to astronomical applications-faster and at lower production costs. Our long-term vision for the new technology is to decrease the mass density (and cost) of mirrors by an order of magnitude.The idea of using force actuator-sensors fabricated from EAPs [3,4] is developed in this work in order to achieve active mirror surface shape control. By manipulating EAPs as active supports, integrated into the mirror structure allows correcting the mirror shape with a continuous actuator force distribution. Figure 1 illustrates how EAPs behave as elastic electromechanical deforming springs. This "electrical polishing" can correct surface shape errors that would be conventionally removed by abrasive grinding. To achieve high optical mirror quality surfaces with a thickness of a few millimeters the EAP glass deformation must have a dynamic range of few microns corresponding to actuator forces of about 1 N. The technique we propose could potentially be achieved using only additive manufacturing via 3D-printing technology.In this article we aim to present the EAP concept for Live-Mirror active optics. We evaluate different polymers in specific actuator designs in order to test their mechanical actuation properties for mirror-actuator prototypes. This article focuses on EAP-based actuator basic properties. Future work will explore how EAP sensors can be integrated into mirror systems.

Advanced Plasticized Electroactive Polymers Actuators for Active Optical Applications: Live Mirror

“…Based on the analysis investigated in previous work, it has been revealed that the plasticized terpolymer exhibits the largest blocking force as opposed to other former EAPs (i.e. F block‐silicone ≈ 5 N, F block‐terpolymer ≈ 50 N, and F block‐plasticized terpolymer ≈ 200 N at applied E = 15 V μm −1 ) . This result allows to confirm high potential of the proposed material in Live Mirror applications.…”

“…Recently, our research collaboration introduced a novel hybrid dynamic live optical surface technique, [26][27][28] which we called the Live Mirror project. Our previous work [29] demonstrated the feasibility of controlling mirror deformation using a single "multilayer plasticized terpolymer" actuator. By inserting an eight-active-layer prestressed actuator between two flat glass plates, a maximum displacement of around 10 μm was attained at a low electric field of 20 V μm À1 .…”

“…This property makes terpolymer one of the most adequate candidates in the astronomical field, especially in active optics controlling, where a high force is necessary to efficiently deform the mirror surface. Indeed, previous studies [29,35] showed that the figure merit of the blocking force strongly depends on the dielectric permittivity of the material. Based on the analysis investigated in previous work, it has been revealed that the plasticized terpolymer exhibits the largest blocking force as opposed to other former EAPs (i.e.…”

Effect of beta-based sterilization on P(VDF-TrFE-CFE) terpolymer for medical applications

“…This phenomenon, however, is not the same as the plasticized EAP where the dielectric losses of both irradiated and pristine samples are almost the same, having negligible discrepancies under the whole frequency range. Because the plasticized terpolymer demonstrated extremely high molecular mobility 30,31 , some ruptured molecular chains from β-radiation processing probably only slightly influenced the polymer structure 32,33 .…”

“…The 3D smart guidewire is performed by extruding an all-organic EAP to design a form of tube. For building a mixture between terpolymer and plasticizer, solution casting method 30 is carried out to create thin film that can be easily cut into small pellets of 5 × 5 mm². The extrusion process starts by feeding the pure or modified terpolymer from a hopper into the barrel of a Laboratory Mixing Extruder (LME, Dynisco, Inc.).…”