Flamethrowers are nothing new, but this punch-activated version just might be the coolest ever. The punch activated part is controlled with an Arduino Pro Mini and an accelerometer. A fist performing a punch has a fairly unique acceleration profile that looks like a significant positive acceleration, followed by an extreme deceleration within a short time window(<100ms), which means the Arduino can distinguish punches from normal everyday gesticulations pretty easily. “Once everything is mounted to an arm, we have a flamethrower that can be actuated by an Arduino only when the arm has thrown a punch,” according to its creator(s). Click here to view the first image in today’s viral picture gallery. Continue reading for a viral video of someone using primitive technology to craft a pair of functional sandals.