SUMMARY
UCLA researchers in the Department of Materials Science and Engineering have developed materials which can be structured to create spectrally selective transmitters and reflectors, which filter out undesirable radiation (e.g. sunlight) and reflect or transmit thermal radiation onto imaging sensors.
BACKGROUND
Thermal imaging, popularly known as heat vision, is an increasingly useful mode of sensing the environment. Thermography offers the ability to “see in the dark,” showing features that traditional photo/videography cannot see. Current consumer grade thermal cameras use geranium, a brittle semiconductor that suffers from noisy background from sunlight, low infrared transmittance (unless antireflection coatings are used), and reduction in transmittance at high temperatures. Most importantly, their high cost makes thermal imaging systems prohibitively expensive. New optical materials are needed to create better reflective and transmissive thermal optical components.
INNOVATION
UCLA researchers have developed spectrally selective materials for reflective and transmissive infrared optical components. The materials can structured to scatter and reflect solar wavelengths, while allowing longer thermal radiation wavelengths to pass through and be imaged. This is useful for transmissive optical systems. Alternatively, they can be used to reflect thermal radiation while absorbing sunlight, for reflective optical systems. In either application, the materials can be used at high or low temperatures and can be conveniently, easily and cheaply manufactured at scale, alone or in combination with other materials.
POTENTIAL APPLICATIONS
- Autonomous vehicles
- Sensing under low visibility or invisible objects
- Transmission optics for imaging systems
- Reflection optics for imaging systems
- Flat, parabolic or spherical mirrors
- Medical diagnostics
- Defense/surveillance
- Quality control
- Industrial production lines
- Building insulation analysis
- Scientific research
- Meteorology
- Studying the atmosphere and weather predictions
ADVANTAGES
- Absorb ultraviolet-to-short wavelength radiation from sunlight
- Improved performance on longer infrared wavelength
- Low cost, by a factor of ~100x based on preliminary estimates.
- Convenient manufacture
DEVELOPMENT TO DATE
Materials have been successfully prototyped and used to demonstrate proof of concept
RELATED PAPERS
https://arxiv.org/abs/2106.14328