Laser Powers Paper Airplanes

A laser-based propulsion system for ultralight aircraft has been demonstrated by researchers at Tokyo Institute of Technology. The technique, which they reported in the June 10 issue of Applied Physics Letters, may find applications in the three-dimensional monitoring of atmospheric CO₂ and in the control of small blimps fitted with antennas for cellular telephones and television.

The team illuminated paper airplanes featuring aluminum ablation structures coated with plastic or with water with 5-ns, 590-mJ pulses of 1064-nm radiation from an Nd:YAG laser. These "exotic" targets confine the ablation of the absorbing layer to amplify the surface pressure and thereby increase thrust by two orders of magnitude, explained Claude R. Phipps of Photonic Associates in Santa Fe, N.M., who provided experimental data to the team. He has investigated the use of lasers to launch satellites, clear debris from orbit and serve as thrusters for spacecraft.

The team illuminated paper airplanes featuring aluminum ablation structures coated with plastic or with water with 5-ns, 590-mJ pulses of 1064-nm radiation from an Nd:YAG laser. These "exotic" targets confine the ablation of the absorbing layer to amplify the surface pressure and thereby increase thrust by two orders of magnitude, explained Claude R. Phipps of Photonic Associates in Santa Fe, N.M., who provided experimental data to the team. He has investigated the use of lasers to launch satellites, clear debris from orbit and serve as thrusters for spacecraft.

Takashi Yabe, lead author of the research, said that the laser propulsion system has since been used with a 10-g rolling vehicle, 100 times heavier than the airplanes. He said that the team plans to float the vehicle with a balloon to demonstrate the feasibility of controlling antenna-bearing aircraft with the technique. Other avenues of investigation may include driving tiny craft through the bloodstream with 10-keV x-rays.