Actuator Device Utilizing Radiative Cooling

The present technology provides an opto-mechanical actuator that converts input optical radiation into mechanical motion. It exploits a novel bidirectional radiative thermal transfer from a hybrid working fluid in a heat engine structure to enable rapid motion within an opto-mechanical actuation system. The hybrid working fluid has the unique composite property of high optical absorption/emission yet low specific heat. Consequently, it can heat and cool rapidly, enabling a much greater cycle frequency and a commensurate increase in specific power, in comparison to conventional closed cycle heat engines for which the cycle frequency is limited by the use of slower, non-radiative, thermal transfer. The device operates as a heat engine that utilizes direct thermal radiation exchange between a working fluid of the actuator and the external environment in order to radiatively cool the working fluid. The working fluid is a hybrid fluid (e.g., argon gas) comprising a compressible fluid and a suspension of electromagnetic radiation-absorbing solid elements that are distributed within the compressible fluid. Examples of suitable compressible fluids include inert gases. Suitable radiation-absorbing elements include graphene or other nanostructured carbon materials. The technology could be applied in a range of size scales (microns to centimeters) and geometries. Paul Cyr paul.cyr@uilo.ubc.ca 604-822-8166