A mixture of vegetable starch and olive oil makes an ultra-cheap shock-absorbing fluid, according to the Defense Development Agency in Korea (US 2004/0021134). Starch is baked dry, then ground into 10-micrometre particles. A trace of water is added to make the starch conduct electricity and the dough is then mixed with olive oil.
When several thousand volts are applied across the mixture, it changes from a freely moving gunge to a near-solid mass that can stiffen shock absorbers in a car or truck. As soon as the voltage is removed, the material reverts to its original texture.
