On a rainy weekend last year, Patrick Priebe, a German lab technician and Iron Man fanatic who rewatches the film and its sequel every week, decided to build a compact yet powerful laser inspired by Tony Stark’s repulsor-beam weapon. In the U.S., the maximum strength for consumer laser pointers is typically five milliwatts; Priebe’s handheld laser is 1,000 milliwatts, enough to instantly blind anyone not wearing special safety glasses.
Priebe began his project by sculpting a two-millimeter sheet of brass into a C-shape so that he would be able to slip the weapon onto his hand. Inside the housing, he made a large ring that holds a laser diode from a Casio projector and works as a heat sink. The device runs on 7.4 volts from lithium-ion batteries, which a component called a driver keeps from spiking dangerously and damaging the diode.