Novel photomechanical actuators

Abstract

The importance of research in optical nano-engineering today is comparable to that of research in semiconductors 60 years ago. Biologically inspired photoactive isomers are being engineered and incorporated into substrates to construct optically addressable nanomachine "laser controlled molecular actuators" which will provide non-contact active figure control, allowing a robust response of lightweight optics to pointing slewing, thermal perturbations, and misalignment. The ability of photoactive molecules to change structure within a matrix in response to light has application to minimizing optical element mass while drastically improving control authority of active optics. Ongoing experiments are providing a foundation for applications in the development of novel optically addressable light-activated shape control of deformable mirrors, as well as addressing issues like damping vibrations after re-pointing large space telescopes. Several types of systems are being studied. The goal is to design and then synthesize materials, generate a picture of molecular scale mechanical forces, bulk geometric distortions, and then to optimize the systems for active optical elements. This requires the design and synthesis of novel photoactive materials. Understanding the molecular-scale motion of photomechanical nano-machines require chemical studies, novel synthesis and fabrication techniques, spectroscopy, imaging molecular-scale mechanical responses and surfaces, optical metrology, and development of novel control techniques. After synthesizing appropriate photoactive substances, active substrates will be produced. A test apparatus is being developed to quantify control authority. Once the chemistry has evolved, a down selection will occur, and new substrates will be fabricated and tested. This talk will report results of this effort.