On 2 May 2016Cambridge researchers have built the world's smallest working engine. The research was published in the journal of the National Academy of Sciences of the United States of America (PNAS).
•    The engine is few billionths of a meter in size and uses light to power itself.
•    The nano scale engine can set a benchmark for nano-machines that can navigate in water, sense the environment around them, or even enter living cells to fight disease.
•    Professor Jeremy Baumberg from the Cavendish Laboratory, who led the research, has named the devices Actuating Nano-Transducers.
•    Device is made of tiny charged particles of gold, bound together with temperature-responsive gel.
•    When the engine is with a laser, it stores large amounts of elastic energy in a fraction of a second.
•    This has the effect of forcing the gold nano particles to bind together into tight clusters.
•    However, when the device is cooled, the polymers take on water and expand, and the gold nano particles are strongly and quickly pushed apart.