A copper camouflage shell, inspired by the chameleon, is the first to render sensors invisible to both thermal and electric image detection.
Current technologies that make sensors “invisible” also usually make them ineffective, while others only work in specific physical fields—either thermal or electrical.
“We have designed a camouflage ‘shell’ that not only mimics surrounding thermal fields but also electric fields, both at the same time. The object under camouflage becomes truly invisible as its shape and position cannot be detected in terms of both thermal and electric images,” says Qiu Cheng-Wei, an assistant professor at the National University of Singapore who led the project.
The sensor is covered in a thin shell of pure copper. The shell is designed to drastically reduce the perturbation of heat flux and electric current simultaneously. The thickness of the shell is fabricated based on detailed calculations to allow precise manipulation of external multi-physical fields to insulate the sensor. This renders it invisible and yet allows it to receive incoming signals from outside.
“Our camouflaging shell will open up a new avenue for advanced sensing and security systems. Sensors that are used to monitor current and heat flow in strong voltage or high temperature environments are easily damaged,” says Qiu.
“Our camouflaging shell hence protects such sensors from the harsh environment and at the same time enhance the accuracy of the hidden sensor, as the shell will eliminate any distortion around the sensor. This attribute is significant in our study of other applications such as using the camouflaging shell on special mission fieldtrips. The team is also working on developing multifunctional invisible sensors that have instantaneous stealth ability.”
The team’s shell design was inspired by the chameleon.
“The skin of a chameleon is made up of several layers of specialized cells containing various pigment while the outermost layer is transparent. The cells beneath the skin change color based on light intensity and temperature as well as the chameleon’s mood.
“Our team’s invention can be seen as an improved ‘skin’ for the chameleon such that it will become invisible when it appears in front of thermal and electric signal detectors,” says Qiu.
Source: National University of Singapore
