Israeli Physicists Develop Advanced Thermal Camouflage
Translated & summarized from NEWSru Israel by baba
Physicists at the Hebrew University of Jerusalem have created an advanced thermal camouflage using a meta-surface that masks objects from dual-spectrum thermal imagers. The technology independently controls thermal radiation in two infrared bands, overcoming limitations of existing camouflage. Demonstrations show distinct images visible in each spectrum, and the material is stable up to 112°C. Potential applications include security features and dynamic thermal displays.
The story in 5 lines · by baba
- Hebrew University physicists created a meta-surface for advanced thermal camouflage.
- The camouflage masks objects from dual-spectrum thermal imagers.
- It independently controls thermal radiation in mid-wave and long-wave infrared bands.
- The material remains effective up to 112°C and at various viewing angles.
- Potential uses include security tags, data encryption, and thermal displays.
Scientists at the Hebrew University of Jerusalem have developed a novel meta-surface capable of manipulating thermal radiation across two infrared spectrums, effectively masking objects from advanced thermal imagers. Traditional thermal camouflage typically works by matching an object's surface reflectivity to its background within a single infrared window. However, modern thermal cameras can operate in two atmospheric "transparency windows", mid-wave (3-5 μm) and long-wave (8-14 μm), and compare images from both, rendering single-window camouflage ineffective.
The breakthrough lies in a meta-surface where the thermal emission in each window can be independently controlled, a feat difficult to achieve with conventional structures whose characteristics are rigidly linked. The researchers created this by depositing an aluminum layer, an amorphous silicon layer, and an array of aluminum micro-disks onto a glass substrate. This structure generates two distinct resonances, one for each infrared window, which can be tuned almost independently by adjusting the disk radius and lattice spacing.
Experiments with 130 different structures demonstrated that the reflectivity in the two ranges could be made practically independent. The team showcased a compelling demonstration on a chip: a thermal imager would see Isaac Newton in the mid-wave spectrum and Gottfried Leibniz in the long-wave spectrum. This thermal camouflage remains effective even when heated up to 112°C and when viewed at an angle. The chip can be manufactured using standard photolithography techniques.
The researchers suggest that this platform could be used for creating anti-counterfeiting security tags and for optical data encryption. They also envision applications in "thermal animation," transforming static camouflage into dynamic thermal displays.