Easton LaChappelle, working on his own, has invented a brain-controlled 3D printed prosthetic arm for $250, potentially replacing similar arms costing $80,000.

Version 3.0 of the robot uses a Teensy Arduino microcontroller as well as amplifier circuits and Bluetooth receivers. To control the arm, the user flexes a muscle to choose from a menu of movements then performs a series of eye blinks to select pre-loaded gestures such as hand, elbow, or wrist movements. Once a movement is selected, an EEG headset measure brainwaves to control the movement. Total cost for the device? $250.