Multi-frequency layered meta-material films and coatings, based on photonic crystal superlattices and nanomaterials. These materials provide a low-cost, tuneable solution that filters specific wavelengths of light whilst retaining transparency across the remaining spectrum.
These stable, thin and flexible films and coatings can be adhered or applied to a range of substrates for applications including protective eyewear, electro-optic protection for cameras and anti-laser dazzle coatings for commercial aircraft.
AMD’s contract with the Irregular Warfare Technical Support Directorate (IWTSD, formerly CTTSO) will fund development of laser filtering coatings, based on AMD's nanomaterial and photonic crystal technologies.
PHOTONIC GAS SENSING
Rapid, highly sensitive and tuneable CBRN sensors
Sensors which focus on the reaction of embedded enzymes within photonic crystals are enabling rapid Chemical, Biological, Radiological and Nuclear (CBRN) indicators designed to better protect soldiers’ lives.
This technology is possible through chemi-resistive, mechano-chromic or chemi-chromic responses, providing improved discrimination and reduced false alarms compared to alternatives. It can be tuned to be ultra-sensitive and specific to particular gases, and by using this sensor technology in an optically active macroscopic matrix for chronometric sensing, a visual indicator is possible.
When incorporated into chemi-resistive sensors, it is possible to achieve electrical read-outs, providing data over time and, therefore, understanding of longer-term exposure, rather than just an instant indication.
The need to hide and identify assets with digital camouflage is an essential and rapidly evolving military need.
Control of apparent thermal emissivity has been demonstrated using 2D graphene to create an ultra-thin electrolytic capacitor to modify the bandgap. The UK MOD has funded prototype development, demonstrating active control of thermal signatures. The ultra-thin, scalable technology enables large-area pixelated arrays for an active digital camouflage to match different scenes or even provide tactical communications.
This technology lends itself to scaling, and work is underway to expand its applications in areas such as adaptive IR optics, heat management and radar mitigation applications.
STRUCTURAL HEALTH MONITORING
Scanning for impact assessment and fault analysis
As composites are used more widely in defence on platforms such as unmanned vehicles, the threat of barely visible impact damage (BVID) and general straining in composites is significant. The need to be able to assess the health of composites, in a non-destructive fashion, is, therefore, essential to improve the quality, capability and in-service lifetime of equipment.
Graphene 2D materials enable mechano-resistive sensing using a stretchable binder to change conductivity under compression or stretching and latex honeycomb or photonic crystals to generate colour changes.
Our prototype sensors have demonstrated a unique combination of extremely high sensitivity and dynamic range. Early fatigue detection−2D nanomaterial combinations have been used to demonstrate detection of early structural fatigue and micro-cracking through change in vibrational (Raman) spectra, providing early identification of potential failure.