Researchers at the University of Cambridge have developed the smallest machine in the world, which could prove very useful in modern medicine. The device is so small that it could be used to enter living cells with the purpose of fight diseases. The small engine is a reflection of the vision in the 1966 classic film Fantastic Voyage, where the submarine crew travels through the body of an injured scientist to repair a blood clot in his brain- except there is no need of shrinking the human pilot.
Nanomachines have long been projected to have the ability to revolutionize technology and modern medicine though challenged by lack of a viable power source to make them move where they are needed. Scientists in Cambridge have solved this by using light to run these engines. The Study co-author, Dr. Ventsislav Valev, noted there was already knowledge than light can heat up water to power steam engine but now light can be used to power a piston engine at the Nanoscale.
The Nano engines are made of tiny gold particles and measure 60 nanometers in diameter. In size comparison, the average human hair is about 100,000 nanometers wide. The particles are connected by a water-laden gel that has been made of a heat-sensitive compound. When heated to more than 35 degrees Celsius (95 Fahrenheit), they expel water contracting within a microsecond, forcing the gold nanoparticles into a tight cluster that is about 400 nanometers wide. When the engine cools, the gel absorbs water and expands resulting in the gold nanoparticles being quickly and forcefully pushed apart like a spring.
Dr. Tao Ding from Cambridge’s Cavendish Laboratory describes the small engines movement like an explosion. He notes that hundreds of gold ball fly apart in a millionth of a second when water molecules inflate the polymer around them. He further notes that they are the most efficient Nano engine to date. They are also energy-efficient, cost-effective, and biocompatible to manufacture.
While the prototype has been made of gold nanoparticles, any dense metal including silver, copper and nickel can be used. Baumberg notes that gold is nice to use since it gives them a color that can be used to infer the separation of nanoparticles.
Professor Jeremy Baumberg from the Cavendish Laboratory, who led the research notes that Just Like real ants, they can produce enormous forces relative to their weights. He further notes that they can get 10 Nano-Newton forces that are about ten to a hundred times more per unit weight than any other known machine. The only challenge they are facing is how to control the force for Nano-machinery application.
The research team is currently in discussion with private companies on how to commercialize the technology for microfluidics bio-applications.
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