Laser radiation causes polymer gel to contract

Agar-like polymer gels contract when heated, but a University of Tokushima group has found that similar reversible contractions can be achieved using laser beams. They used a finely focused laser beam directed onto the polymer gel and demonstrated that material around the beam spot readily deforms.

Experiments showed the gel contracts not because of heat generated by the laser, but due to the radiation forces of the light itself. The potential applications of such a polymer gel include actuators and sensors, micromachine valves that can be opened and closed with a beam of light, and even light-controlled artificial muscles.

The group is now co-operating with Matsushita-Kotobuki Electronics Industries to exploit the new technology for the commercial development of blood-glucose sensors.