A bat detector is an indispensable tool for anyone studying bats in the field. The detector enables you to hear the otherwise inaudible ultrasonic calls of the bats. This is most useful to identify different species as well as just determining bat activity.

When you want to move your body, your brain sends out an electric signal that is received by your muscles, which then contract, thus producing motion. This electric signal travels to the muscles via the body's nerves, generating a slight voltage of electricity on the surface of the skin. This is known as a bioelectric signal, and Robot Suit HAL detects them using the sensors placed around the wearer's body. Depending on the voltage running the surface of the skin, the computer inside Robot Suit HAL analyzes the signal and sets the appropriate motors in motion.

This unique method of operation means that a person can control Robot Suit HAL by his or her own will, even if he or she is unable to actually move. And as the suit detects the signal sent from the brain even before it gets to the muscle, it can move an instant before the muscle does.

there is a hobby that nobody talks about called circuit bending. It's great fun, I've done it a few times and I've got a few friends that are really into it. Circuit bending is the act of cracking open a musical toy,radio, tape machine, cd player, walkie-talkie etc. and hapazardly/randomly poking around the ciruit board with a couple of wires to get unique sounds out of whatever you're "bending". You then solder the wire at the points you want and voila, you have a brand new musical insrument. Some people get really crazy with it and add new parts like light sensors, switches, buttons etc. and get some really wild effects.