Laser guns are cool. And, I plan on publishing about Tactical High Energy Lasers in the future. But, I happened on a very interesting technology based weapon that is not a laser, but is a directed-energy weapon,  and thought it was worth sharing. Meet the Active Denial System.


The Active Denial System or ADS is a non-lethal, directed-energy weapon system under development by the U.S. military. It is a strong millimeter-wave transmitter used for crowd control. Raytheon is currently marketing a reduced range version of this technology.

The ADS works by directing electromagnetic radiation at a frequency of 95 GHz toward the subjects. The waves excite water molecules in the epidermis to around 55 °C (130 degrees Fahrenheit), causing an intensely painful burning sensation. While not actually burning the skin, the burning sensation is similar to that of a hot light bulb being pressed against the skin. And, we all know how much fun that can be.

The focused beam can be directed at targets at a range of just under half a kilometer, or 500 yards. The device can penetrate thick clothing, although not walls. There is no indication on the feasibility of electromagnetically shielding a person from its effects with a wire mesh or Faraday cage, in a similar manner that a microwave oven prevents radiation escaping. As the beam excites the water molecules in the skin, water bearing materials such as wet clothing/towels, wet pastes/gels, vegetables or meat could effectively absorb the energy, although the military claims that wearing wet clothing actually intensifies the effect. So, go figure.

At 95 GHz, the frequency is much higher than the 2.45 GHz of a microwave oven. This frequency was chosen because due to the stronger absorption of water at those frequencies, they penetrate the skin to a depth of less than 1/64 of an inch (0.4 mm), which is where the nerve endings are located. A spokesman for the Air Force Research Laboratory described his experience as a test subject for the system: "For the first millisecond, it just felt like the skin was warming up. Then it got warmer and warmer and you felt like it was on fire.... As soon as you're away from that beam your skin returns to normal and there is no pain." 

Oh, what I could do with this and about 500 cases of Jiffy Pop