A new generation of sensors for detecting explosives and poisons could be developed following new research into a type of radiation known as T-rays. The research shows that these T-rays, electromagnetic waves in the far infrared part of the electromagnetic spectrum that have a wavelength 500 times longer than visible light, can be guided along the surface of a specially designed material, known as a metamaterial. Being able to control T-rays in this way is essential if this type of radiation is to be used in many real world applications.