HYBRID DYNAMIC STRUCTURES FOR OPTICAL-QUALITY SURFACES SHAPE CONTROL – LiveMetaOptics
HYBRID DYNAMIC STRUCTURES FOR OPTICAL-QUALITY SURFACES SHAPE CONTROL
Optical communication and remote sensing (ground & space) including astronomy requesting high-dynamic range observations are the next frontiers in high-bandwidth communication and civil space surveillance technologies. Each requires very precise glass mirror technology, which has not kept pace with corresponding optical and infrared sensor advances. Consequently communication & remote sensing systems are currently limited by the cost and manufacturing restrictions of their high-quality optics.
Breaking areal density, stiffness, and surface smoothness limits with additive (non-abrasive) 3D-Printed new technologies
The novelty is to replace classical rigid and heavy optical mirrors with “live” and light dynamic optoelectronic systems consisting of a thin optical fire-polished glass sheet actively “live” supported by many-degree-of-freedom force-actuators/sensors integrated and miniaturized via additive manufacturing and 3D printing. Our 3-key novel technology are: (1) Develop a “deterministic non-contact glass slumping” (DNCGS) technique that generates optically accurate aspheric shapes from commercial fire-polished “float” glass with extremely smooth optical surface which is never abrasively polished or surface-contacted. This yields an aspheric shape that is within a few microns of the desired precisely-shaped optical surface. (2) Achieve active shape control with many-degree-of-freedom force actuators and sensors created by an additive 3D-printing-based technology that relies on an optimized electroactive polymer (EAP) systems in a sandwich of DNCGS glass surfaces. This creates a novel hybrid meta-material with superior stiffness-to-density ratio properties. (3) Such hybrid structures will require a fast and efficient optical calibration technique. Our “3D-printed” force actuator and sensor system works in combination with an optical metrology and Kirchhoff-Love solver control algorithm, integrated into a highly-parallel information network system allowing dynamic maintenance of a desired large-scale single mirror shape. The breakthroughs targeted by this technology are: significantly lower areal mass density of optical mirrors (x7); significantly improved surface roughness and lower scattered light (x10) and significantly shorten production time and lower cost (x15). These achievements, for many applications, will supersede conventional subtractive abrasive polishing mirror technologies, realizing highly accurate optical surfaces with high smoothness and without expensive abrasive polishing.
Our research methodology is defined by the project objectives and addresses the challenges of the proposed new technology. Its interdisciplinary nature is rooted in its components with contributions from different fields and is the major and crucial issue for its success: (1) radically interdisciplinary new technology: to produce high-precision optics at fast rate and low cost, combining optics mass production material with advanced glass processing technology, new actuator principles based on additive fabrication combined with a scalable sensor communication network, optical nano-metrology and new geometric shape algorithms. (2) cutting-edge science and innovation practice: deterministic scientific approach, i.e., modelling and predicting the result for all new key technology components: slumping, hybrid 3D-printed active support, and system integration, with an initial driving force being an astronomy need for extremely large telescopes but the final goal is to be compliant with the growing societal challenges; (3) early detection of promising new area: extremely precise and light-weight optics for space; (4) interdisciplinary collaboration: 3D-printed force actuators and sensors additively tailored to the metamaterials (material and manufacturing sciences), optics, metrology, glass industry, information technology and astronomy; (5) combination of blue-sky science and research driven by industrial competitiveness in order to respond to societal challenges: from astronomy to optics production and to communication, security, and resources. Our project is producing and testing a scalable ½ meter class diffraction-limited imaging system for demonstrating objectives (1) to (3) above section. The R&D issues already are and will continue to be subject of on bench work to improve technology readiness level and minimize the risk. In the end each technology component will be developed to allow future scaling of the prototype up to 5m mirror.
The first realisation in Lab of a fully 3D printed electroactive force-actuator system optimized through its electromechanical characterization as well its multilayer structure design: a modified terpolymer layer sandwiched between two layers of conductive terpolymer composite, i.e. a compatible carbon black composite layer with optimized electrical conductivity enabled to operate under high voltage. The full-force-actuator and their related electrodes were 3D printed on the back of a flat glass substrate (the prototype mirror optical surface) displaying a compliant electromechanical transfer response deforming the single glass substrate of micron range depending on the number of actuators across the glass substrate and the electrode size i.e. the actuator active-size. The attached illustration shows the preliminary results for a four force-actuators setup based on a doped terpolymer P(VDF-TrFE-CFE) 8wt% DINP 3D printed on the back of optical surface (glass plate 2mm x 110mm in diameter).
Such a preliminary very conclusive results show the potential of developing full-printed soft force-actuators allowing the feasibility of free-form-actuators devices. Additive manufacturing via 3D printing technology is promising step opening the door to large-area of electromechanical devices and actuator applications, such as optical light and large “live” mirrors demonstrating the potential for new remote sensing capabilities from the ground and from space.
Announcement was done on our project webpage ( www.planets.life/live-mirror ) – Go to project webpage to “green” free open access to the project referred journals and conferences publications.
Beyond T0+18Months project next steps are (1) to improve our fully 3D-printed development to several (tens) of dedicated-multi-layer force-actuators and their related electrodes miniaturization; (2) development of sensor-layer; (3) close the loop of sensor-actuators via optical metrology and Kirchhoff-Love solver control algorithm, integrated into a highly-parallel information network system allowing dynamic maintenance of a desired large-scale single mirror shape (e.g., on- and/or off-axis parabola for example); (4) in parallel develop a new technique to co-phase “sparse” interferometric arrays of hundreds mirrors (e.g. globally an extremely large optical surface) with precision of 10’s nanometers in order to minimize the wave front errors which degrade the image quality is a crucial and fundamental issue to be solved in order to validate the extremely large telescopes (ground or space based) for astronomy, optical communication and remote sensing systems. This objective will be demonstrated with extensive realistic models and (5) collaborate with ATRC/University of Hawaii with long period missions to close the “deterministic non-contact glass slumping” (DNCGS) technique that generates optically accurate aspheric shapes from commercial fire-polished “float” glass with extremely smooth optical surface which is never abrasively polished or surface-contacted. This yields an aspheric shape that is within a few microns of the desired precisely-shaped optical surface via sensor-force-actuators fully 3D-printed.
Project Team Publications:
1. Surface Correction Control Based on Plasticized Multilayer P(VDF-TrFE-CFE) Actuator – Live Mirror, Adv. Optical Mater. 2019, 1900210.
2. Advanced Plasticized Electroactive Polymers Actuators for Active Optical Applications: Live Mirror, Adv. Eng. Mater. 2020, 22, 19015-40.
3. In preparation - 3D Printed Electroactive Terpolymer Actuators Allowing Novel Optical Live-Mirror Applications, (2020).
Conferences Proceedings Publications:
1. Hybrid Dynamic Structures for Optical-Quality Surfaces Shape Control: Live-Mirror, Talk in the 11th International Conference on Optics-photonics Design & Fabrication, The Optical Society of Japan, Hiroshima, Japan, 28-30 November (2018).
2. Invited Talk to Quantum Sensing and Nano Electronics and Photonics XVI; SPIE OPTO, Proc. of SPIE Vol. 10926 109261X-1, (2019).
3. Live-mirror shape correction technology operated through modified electroactive polymer actuators, in Proc. SPIE 10966, Electroactive Polymer Actuators and Devices (EAPAD) XXI, 109662U (13 March 2019); SPIE Smart Structures + Nondestructive Evaluation, (2019).
4. The Exo-Life Finder (ELF) Telescope – Optical Concept and Hybrid Dynamic Live-Optical Surfaces Startegies, In the Spirit of Lyot Meeting; Instrumentation and Technology Section, Tokyo, Japan, Oct. 21-25, (2019).
5. Advanced 3D-printed EAP actuator applied to high precision large optical-quality surface fabrication: first results. In Electroactive Polymer Actuators and Devices (EAPAD) XXII (Vol. 11375, p. 113751X). International Society for Optics and Photonics, April (2020).
Project PhD. Thesis: “Development of Electroactive Polymer Actuators for Next Generation Mirror: LIVE-MIRROR”, by K. Thetpraphi.
Optical communication and remote sensing (ground & space) are the next frontiers in high-bandwidth communication and civil space surveillance technologies. Each requires precise glass mirror technology, which has not kept pace with corresponding sensor advances. Consequently communication and remote sensing systems are currently limited by the cost and manufacturing restrictions of their optics. We propose to develop a new and interdisciplinary technology breaking cost, areal density, stiffness, and surface smoothness limits with additive (non-abrasive) new manufacturing: Live-MetaOptics. Proposal new key components & objectives are: (1) develop a new deterministic non-contact glass slumping technique from commercial fire-polished thin glass; (2) develop a new hybrid 3D-printed active mirror shape control system with accurate force/sensor; (3) develop a new fast and efficient optical calibration technique and (4) a new technique to co-phase “sparse” interferometric arrays of hundreds mirrors. This project will produce and test a scalable ½ meter class Live-MetaOptics diffraction-limited imaging system for demonstrating objectives 1 to 4 above. In the end the demonstrator will validate Live-MetaOptics mirror in terms of Image Quality & High-Dynamic Range performances!
Monsieur GIL MORETTO (Centre de recherche astrophysique de Lyon)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
ATRC Institute for Astronomy, University of Hawaii / Advanced Technology Research Center
LGEF - EA682 LABORATOIRE DE GENIE ELECTRIQUE ET FERROELECTRICITE
CRAL Centre de recherche astrophysique de Lyon
Help of the ANR 406,102 euros
Beginning and duration of the scientific project: September 2018 - 48 Months