Nanomotors could help electronics fix themselves

As electronics grow ever more intricate, so must the tools required to fix them. Anticipating this challenge, scientists turned to the body’s immune system for inspiration and have now built self-propelled nanomotors that can seek out and repair tiny scratches to electronic systems. They could one day lead to flexible batteries, electrodes, solar cells and other gadgets that heal themselves.- The researchers present their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS).- “Electronic circuits are very sophisticated these days,” says Jinxing Li. “But a crack, even an extremely small one, can interrupt the flow of current and eventually lead to the failure of a device. Traditional electronics can be fixed with soldering, but repairing advanced electronics on a nanoscale requires innovation.” Gadgets will soon be more ubiquitous than ever, appearing in our clothes, implants and accessories, says Li, a Ph.D. candidate in the lab of Joseph Wang, D.Sc., at the University of California at San Diego. But finding ways to fix nanocircuits, battery electrodes or other electronic components when they break remains a challenge – Replacing whole devices or even parts can be tricky or expensive, particularly if they’re integrated in clothes or located in remote places. Creating devices that can fix themselves would be ideal, according to Wang, whose lab develops nanoscale machines. To work toward this goal, his lab and others have turned to nature for ideas.- “If you cut your finger, for example, platelets will automatically localize at the wound location and help start the healing process,” Li says. “So what we wanted to do is create and use extremely small robots to perform the same function, except in an electronic system.” To accomplish this, Wang’s team collaborated with the group of Anna Balazs, Ph.D., who is at the University of Pittsburgh. They designed and built nanoparticles out of gold and platinum that are powered by hydrogen peroxide. The platinum spurs the fuel to break down into water and oxygen, which propels the particles. Testing showed that the nanomotors zoomed over the surface of a broken electronic circuit connected to a light-emitting diode, or LED. When they approached the scratch, they got lodged in it and bridged the gap between the two sides. Because the particles are made of conductive metals, they allowed current to flow again, and the LED lit up.- Li says the nanomotors would be ideal for hard-to-repair electronic components such as the conductive layer of solar cells, which are subject to harsh environmental conditions and prone to scratching. They could also be used to heal flexible sensors and batteries, which the Wang lab is also developing.- Additionally, the same concept with different materials and fuels could be used in medical applications for delivering drugs to specific locations. The lab is also developing new nanomotors that could potentially be deployed in the body to treat different diseases, such as stomach infections.-Story Source-The above post is reprinted from materials provided by American Chemical Society. -American Chemical Society. “Nanomotors could help electronics fix themselves.” ScienceDaily. ScienceDaily, 14 March 2016. <www.sciencedaily.com/releases/2016/03/160314084817.htm>.
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Nanomotors are controlled, for the first time, inside living cells

For the first time, a team of chemists and engineers at Penn State University have placed tiny synthetic motors inside live human cells, propelled them with ultrasonic waves and steered them magnetically. It’s not exactly “Fantastic Voyage,” but it’s close. The nanomotors, which are rocket-shaped metal particles, move around inside the cells, spinning and battering against the cell membrane.
“As these nanomotors move around and bump into structures inside the cells, the live cells show internal mechanical responses that no one has seen before,” said Tom Mallouk, Evan Pugh Professor of Materials Chemistry and Physics at Penn State. “This research is a vivid demonstration that it may be possible to use synthetic nanomotors to study cell biology in new ways. We might be able to use nanomotors to treat cancer and other diseases by mechanically manipulating cells from the inside. Nanomotors could perform intracellular surgery and deliver drugs noninvasively to living tissues.”–The researchers’ findings will be published in Angewandte Chemie International Edition on 10 February 2014. In addition to Mallouk, co-authors include Penn State researchers Wei Wang, Sixing Li, Suzanne Ahmed, and Tony Jun Huang, as well as Lamar Mair of Weinberg Medical Physics in Maryland U.S.A.
Up until now, Mallouk said, nanomotors have been studied only “in vitro” in a laboratory apparatus, not in living human cells. Chemically powered nanomotors first were developed ten years ago at Penn State by a team that included chemist Ayusman Sen and physicist Vincent Crespi, in addition to Mallouk. “Our first-generation motors required toxic fuels and they would not move in biological fluid, so we couldn’t study them in human cells,” Mallouk said. “That limitation was a serious problem.” When Mallouk and French physicist Mauricio Hoyos discovered that nanomotors could be powered by ultrasonic waves, the door was open to studying the motors in living systems.–For their experiments, the team uses HeLa cells, an immortal line of human cervical cancer cells that typically is used in research studies. These cells ingest the nanomotors, which then move around within the cell tissue, powered by ultrasonic waves. At low ultrasonic power, Mallouk explained, the nanomotors have little effect on the cells. But when the power is increased, the nanomotors spring into action, moving around and bumping into organelles — structures within a cell that perform specific functions. The nanomotors can act as egg beaters to essentially homogenize the cell’s contents, or they can act as battering rams to actually puncture the cell membrane.
While ultrasound pulses control whether the nanomotors spin around or whether they move forward, the researchers can control the motors even further by steering them, using magnetic forces. Mallouk and his colleagues also found that the nanomotors can move autonomously — independently of one another — an ability that is important for future applications. “Autonomous motion might help nanomotors selectively destroy the cells that engulf them,” Mallouk said. “If you want these motors to seek out and destroy cancer cells, for example, it’s better to have them move independently. You don’t want a whole mass of them going in one direction.”The ability of nanomotors to affect living cells holds promise for medicine, Mallouk said. “One dream application of ours is Fantastic Voyage-style medicine, where nanomotors would cruise around inside the body, communicating with each other and performing various kinds of diagnoses and therapy. There are lots of applications for controlling particles on this small scale, and understanding how it works is what’s driving us.”-Story Source-The above post is reprinted from materials provided by Penn State. The original item was written by Krista Weidner. Journal Reference-Wei Wang, Sixing Li, Lamar Mair, Suzanne Ahmed, Tony Jun Huang, Thomas E. Mallouk. Acoustic Propulsion of Nanorod Motors Inside Living Cells. Angewandte Chemie International Edition, 2014–Penn State. “Nanomotors are controlled, for the first time, inside living cells.” ScienceDaily. ScienceDaily, 10 February 2014. <www.sciencedaily.com/releases/2014/02/140210095359.htm>.