We report on optical design and applications of hybrid meso-scale devices and materials that combine optical and thermal management functionalities owing to their tailored resonant interaction with light in visible and infrared frequency bands. We outline a general approach to designing such materials, and discuss two specific applications in detail. One example is a hybrid optical-thermal antenna with sub-wavelength light focusing, which simultaneously enables intensity enhancement at the operating wavelength in the visible and reduction of the operating temperature. The enhancement is achieved via light recycling in the form of whispering-gallery modes trapped in an optical microcavity, while cooling functionality is realized via a combination of reduced optical absorption and radiative cooling. The other example is a fabric that is opaque in the visible range yet highly transparent in the infrared, which allows the human body to efficiently shed energy in the form of thermal emission. Such fabrics can find numerous applications for personal thermal management and for buildings energy efficiency improvement.
By dispersing graphene nanoplatelets (GNPs) within a polydimethylsiloxane matrix, we show that light
absorption by GNPs and subsequent energy transduction to the polymeric chains can be used to controllably produce
significant amounts of motion through entropic elasticity of the pre-strained composite. Using dual actuators, a twoaxis
sub-micron resolution stage was developed, and allowed for two-axis photo-thermal positioning (~100 μm per
axis) with 120 nm resolution (feedback sensor limitation), and ~5 μm s-1 actuation speeds. A PID control loop
automatically stabilizes the stage against thermal drift, as well as random thermal-induced position fluctuations (up
to the bandwidth of the feedback and position sensor).
It is highly likely that future micro and nano-mechanical systems will be powered by light. However, the development of
such micro and nano-mechanical systems is still in its infancy. Potential advantages include remote triggering and
actuation, remote energy transmission, solar energy scavenging for useful work, and wavelength selectivity of actuation.
In recent years, carbon based nano-materials such as carbon nanotubes have shown highly interesting optical to
mechanical energy conversion. The development of optical to mechanical energy transducing mechanisms into practical
applications is still in its infancy. Only a few devices have been reported till date. This paper presents some of the recent
developments in the area of nanotube based photomechanical actuators with emphasis on micro and nanooptomechanical
systems. Devices namely micro-cantilevers for detection of free PSA, micro-grippers for manipulation
of small particles and micro-mirrors for light modulation have been developed that show both translational and
rotational actuation. Finally, integrating nanowires on these platforms could lead to the development of nanooptomechanical
systems. The future research of such systems and how they can play an integral part in electronics,
sensing and actuation by integrating nanotechnology with mechanics, optics and electronics is discussed.o