Photomechanical Material Systems: From Molecules to Devices
Abstract
The energy used by military forces has traditionally been delivered as chemical fuel or electrical current. Recent advances in optical technology, however, now make it possible to envision a third mode of energy transport: light propagating through an optical fiber or free space. Photons have multiple enabling advantages as energy carriers: (i) their delivery does not require physical contact with the actuator, enabling remote wireless control; (ii) they possess noninteracting internal degrees of freedom (wavelength, mode, polarization) that allow for multiplexing; (iii) they are immune to electromagnetic interference, e.g., from radio-frequency waves; and (iv) they can be efficiently transported by lightweight and corrosion-resistant optical fibers. However, a critical obstacle to the use of photons as fuel is the lack of materials that can efficiently, reliably, and reversibly convert light to mechanical work. There have been few if any attempts to systematically characterize, model, and engineer this emerging class of materials, and to rapidly advance the field, a multi-scale approach is required spanning disparate fields, from molecular photochemistry to solid-state materials science and physics to mechanical engineering. To develop the fundamental understanding that will enable revolutionary advances in the transformation of light into work, we have assembled a highly interdisciplinary MURI team led by Ryan Hayward (University of Massachusetts Amherst) along with collaborators at the California Institute of Technology, Kent State University, Stanford University, the University of California Riverside, and the University of California Santa Barbara. The team unites expertise in theory, computation, and experiment across length and time scales and material systems. This MURI, titled ???Photomechanical Material Systems???From Molecules to Devices??? is submitted to ONR MURI Topic 21: Advanced Optical Materials that Create Force from Light. The approach involves three interrelated efforts that tightly integrate theory and experiment to design and characterize photomechanical materials from nano- to macro-scales: Molecular Design: We will develop new photoreactive molecules that provide large shape changes and efficient work output by tuning energy levels and molecular conformations. This effort will focus on the synthesis and characterization of these molecules, as well as quantum mechanical modeling to predict their behavior. Materials Development: We will control the organization of photoreactive molecules and host material properties to efficiently translate molecular response to mesoscale deformation. This effort will involve new approaches to material fabrication and engineering, and modeling and characterization of photophysical and mechanical responses. Device Fabrication: We will incorporate photomechanical materials into actuator configurations to allow for robust evaluation of material performance, and in architectures that provide novel functionality of direct relevance to naval applications. This effort requires the engineering and evaluation of devices, and the development of multi-physics models describing opto-mechanical responses. The proposed research will greatly advance basic understanding of photomechanical systems and drive the creation of new, vastly improved materials with promise to have revolutionary impacts on DoD capabilities. By opening the door to lightweight, light-driven devices, optimized photomechanical materials will permit photons, with all their advantages, to replace chemical or electrical power supplies in traditional actuator applications. Optical engineering will allow these systems to be designed with integrated power supply, control, and feedback. Furthermore, the ability to change an object???s shape or motion using light opens the door to totally new applications, like micro-swimmers or surface morphing, that could enable a variety of new capabilities with relevance to DoD.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 26, 2018
- Source ID
- N000141812624
Entities
People
- Ryan C Hayward
Organizations
- Office of Naval Research
- United States Navy
- University of Massachusetts