Based on "ArduSnake library: Locomotion of modular snake robots" by ObiJuan. (http://www.thingiverse.com/thing:21401)
By means of Bluetooth communication, the 4 characteristic parameters of the 2 oscillators, can be modified: amplitude, frequency, phase and offset.
With the sign of the phase value, you can change the movement direction: forward or backward. If the oscillators have the same value of phase, movement is not achieved.
By varying the offset value (midpoint of the oscillations) the device can move in different directions.
A video can be found here: http://youtu.be/MMdTZWX3w0k
More info in my Blog: http://madebyfrutos.wordpress.com/2012/08/14/water-oscillators/
Print the parts and cut from a piece of foam, a circumference of 12 cm in diameter. With a cutter,make some holes to keep the electronic parts inside. (Warning: Don't hurt you!)
I've used one Arduino pro mini, two servos (medium size), a cheap bluetooth modem and a 9v battery. (Optionally, you can use also a 7805 to regulated the voltage to 5v)
The code is based on "ArduSnake library: Locomotion of modular snake robots" by ObiJuan. (http://www.thingiverse.com/thing:21401)
I've improved the bluetooth communication, in that way, you can modify the 4 characteristic parameters of the oscillators easily in real time.