Students will mimic nature by building a snake robot that uses two surface temperature sensors to detect its prey.
Snakes that belong to the pit viper family are named for the heat-sensing organs located near the eyes, known as pits. This allows pit vipers to quickly and accurately find their prey. While our robot won't strike within milliseconds, it can find prey using its own Vernier Surface Temperature Sensors as pits.
First, a metal can is filled with hot water. The greater the difference in water temperature to surrounding air temperature, the easier it is to find prey. Once the robot is started, the pit viper compares the two temperatures and moves in the direction of the warmer sensor. If the snake overcompensates or its prey moves, the snake changes directions. When the difference in temperature is consistently zero, the snake strikes.
This model was built using three 40-tooth gears to alter the gear ratio. Each NXT kit only comes with two 40-tooth gears, so you may need to substitute the turntable for the 40-tooth gears if you only own one kit. The last photo uses a turntable.
Upon completion of this lab, students should: