"This process is comparable to how human vision combines red, green, and blue light to perceive colour."
A New Infrared Filter Fits in the Palm of Your Hand
A team of researchers from The University of Western Australia and The Australian National University, working through the ARC Centre of Excellence for Transformative Meta-Optical Systems, has developed a microscopic, electrically tuneable infrared filter.
The device operates in the long-wave infrared region and is intended to enable compact, low-power spectral sensing.
Device Design and Operation
The filter is constructed as a "sandwich" of suspended gold and silicon membranes that contain nanoscale holes. Applying an electric voltage alters the gap between these layers by a few hundred nanometres. This change determines which infrared wavelengths, specifically around 10 microns, are permitted to pass through the device.
Purpose and Functionality
The technology is designed to allow infrared systems to identify materials and gases by their spectral fingerprints, moving beyond the capability of conventional thermal cameras, which only measure heat intensity.
Lead author Oleg Bannik, a PhD candidate at the UWA School of Engineering, stated that the device could enable cameras to compare multiple infrared bands. This process is comparable to how human vision combines red, green, and blue light to perceive colour.
Potential Applications
Possible applications for the filter include:
- Environmental monitoring (e.g., detecting methane leaks and industrial emissions)
- Industrial safety
- Thermal imaging
- Medical diagnostics (e.g., identifying inflammation and monitoring wounds)
- Defence systems
The low weight and low power requirements of the device make it suitable for integration into drones and portable field systems.
Publication and Context
The research was published in the journal Advanced Materials Technologies. According to the researchers, the device addresses the historical limitation of infrared spectroscopy, which has been largely restricted to laboratories, military systems, and expensive industrial equipment due to its size and power demands.