A high power tunable light source for new photomechanical materials development
Abstract
The development of high power lasers and optical fibers for high power transmission hasopened the door to the use of light to drive mechanical devices directly, withouttransforming photon energy to electricity, heat or other forms of energy. To accomplishthis, new photomechanical materials, capable of directly transforming light energy intomechanical work, are currently under development. A variety of mechanisms exist fortransforming light to work. The direct conversion of light to work begins with thephotoisomerization of chromophores. Here molecules in excited states after absorbingphotons relax to states with different molecular configurations than their initial groundstates. The molecular shape changes result in changes in the shape, volume, stiffness, andother physical properties of the bulk sample, resulting in mechanical work. Thedevelopment of materials capable of efficient transformation of light to mechanical workis of tremendous practical importance. For example, it would enables shape changingactuators to control aircraft wing flaps directly using light delivered via thin and lightoptical fibers, eliminating electric motors, wiring, and rack and pinion gearsets.The development of photomechanical materials involves not only the design andsynthesis of chromophores, but also their integration into hosts or the production of purebulk materials. Promising materials range from liquid crystal gels, rubbers and networksto organic crystals and nanocomposite structures. Key characterization of these materialsinvolves determining their response to light. This involves careful study of their opticaland optomechanical properties. Absolutely essential to this work is a versatile lightsource, whose wavelength, bandwidth and intensity can be precisely controlled. Highpower is required to determine the photomechanical response in the linear regime. TheKiloArc source by Horiba is such a source. In addition, spatial modulation of the light isrequired to determine spatial dispersion of the response. The high resolution Pluto2spatial light modulator by Holoeye is well suited for this purpose. Experimental resultsfrom such measurements will provide the required feedback to the molecular and bulkcomposite designers to enable and accelerate the development of these exciting newphotoactive materials.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 31, 2020
- Source ID
- N000142012780
Entities
People
- Peter Palffy-Muhoray
Organizations
- Kent State University
- Office of Naval Research
- United States Navy