Making undetectable sensing possible

Making undetectable sensing possible

Associate Professor Qiu Cheng Wei (right) and Ph.D. student Bai Xue (left) with the result of their research.

For their innovative discovery, Associate Professor Qiu Cheng Wei and his team from the Department of Electrical & Computer Engineering have the humble chameleon to thank. The lizard has inspired the NUS Engineering team to develop the camouflage shell.

They have developed the world’s first innovative camouflage shell that hides both thermal and electronic sensors simultaneously and effectively, without compromising performance. The technologies that are available today to make sensors ‘invisible’ also make them ineffective, or they only allow the sensors to work in one specific environment – either thermal or electrical.

In numerous research experiments conducted over the past fourteen months, the NUS Engineering team has developed an ideal ‘invisible’ sensor by covering it with a thin shell made of pure copper, designed to significantly reduce the perturbation of heat flux and electric current simultaneously. The thickness of the shell is manufactured based on the detailed calculations to allow precise manipulation of external multi-physical fields to insulate the sensor. Hence, once the shell is wrapped around the sensor, the coated sensor becomes ‘invisible’ in both thermal and electric environments, and still continues to receive incoming signals from outside.

Explained Associate Professor Qiu, ”We have designed a camouflaging 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.

While remaining invisible, the object under camouflage can continue to probe the temperature and voltage in the environment that they are located.”

Associate Professor Qiu also added that their camouflaging shell could potentially open up a new avenue for advanced sensing and security systems. “Sensors which are used to monitor current and heat flow in strong voltage or high temperature environments are easily damaged. Our camouflaging shell can protect the sensors from the harsh environment, and enhance the accuracy of the invisible sensors as they eliminate any distortion around the sensors.

This feature is key 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. Drawing a comparison with the chameleon, Associate Professor Qiu said, “The skin of a chameleon is made up of several layers of specialised cells containing various pigments, while the outermost layer is transparent. The cells beneath the skin change colour, based on light intensity, temperature, as well as the chameleon’s mood. Our team’s creation can be seen as an improved “skin” for the chameleon, so that it will become invisible when it appears in front of thermal and electric signal detectors!”

The researchers estimate that a palm-size camouflaging shell will cost less than S$80.00, as the shell is fabricated from naturally available materials, such as pure copper and stainless steel. They are also in talks with power companies and funding agencies to explore the potential of translation to fabrication.

Related Links:

Experimental Video on Youtube:

The Straits Times: