By using bacterial flagella as a template for silica, researchers have demonstrated an easier way to make propulsion systems for nanoscale swimming robots.
A feature of science fiction stories for decades, nanorobot potential ranges from cancer diagnosis and drug delivery to tissue repair and more. A major hurdle to these endeavors, however, is finding a way to cheaply make a propulsion system for these devices. New developments may now propel nanoswimmers from science fiction to reality thanks to unexpected help from bacteria.
An international research team has demonstrated a new technique for plating silica onto flagella, the helix-shaped tails found on many bacteria, to produce nanoscale swimming robots. As reported this week in APL Materials, from AIP Publishing, the group’s biotemplated nanoswimmers spin their flagella thanks to rotating magnetic fields and can perform nearly as well as living bacteria.
“We have shown for the first time the ability to use bacterial flagella as a template for building inorganic helices,” said MinJun Kim, professor of mechanical engineering, Lyle School of Engineering at Southern Methodist University and one of the authors of the paper. “This is quite a transformative idea and will have a great impact on not only medicine but also other fields.”
Compared to larger forms of aquatic motion, nanoswimming hinges on an understanding of the Reynolds number, the dimensionless quantities that relates fluid velocity, viscosity and the size of objects in the fluid. With a Reynolds number of one-millionth our own, bacteria must use nonreciprocal motion in the near absence of inertial forces. Using helical tails made of a protein called flagellin, many species of bacteria navigate these microscopic conditions with relative ease.
“If we were shrunk down to the size of a bacteria, we would not be able to use the breast stroke to move through water,” Kim said. “If bacteria were the size of us, they could swim 100 meters in about two seconds.”
Other recently developed methods for constructing these helical structures employ complicated top-down approaches, including techniques that involve self-scrolling nanobelts or lasers. The use of this specialized equipment can lead to very high startup costs for building nanorobots.
Instead, Kim’s team used a bottom-up approach, first culturing a strain of Salmonella typhimurium and removing the flagella. They then used alkaline solutions to fix the flagella into their desired shape and pitch, at which point they plated the proteins with silica. After that, nickel was deposited on the silica templates, allowing them to be controlled by magnetic fields.
“One challenge was to make sure we had helices with the same chirality. If you rotate a left-handed helix and a right-handed helix the same way, they will go in different directions,” Kim said.
STEM image of silica templated flagella; scale bar is 1 ?m.
CREDIT: Jamel Ali
The team took their nanorobots for a spin. When exposed to a magnetic field, the nanorobots kept up the pace with their bacterial counterparts and were projected to be able to cover 22 micrometers, more than four times their length, in a second. In addition to this, the team was able to steer the nanoswimmers into figure-eight paths.
While Kim said he sees potential for nonconducting nanoscale helices in the area of targeted cancer therapeutics, he added that with his team’s work, one might plate conductive materials to flagella and produce helical materials for electronics and photonics.
The Latest on: Nanobots
- Could this metal inspired by spiders and ants create an ‘unsinkable ship’?on November 8, 2019 at 2:12 am
Researchers are very excited about a metal that refuses to sink, rising to the surface even after months of being submerged. What are the possibilities of a metal that is so water resistant ...
- Nanobots Market Size Is Projected to Reach USD 100 Billion at a CAGR Of 21% Owing To Technological Developments In Robotics By 2023on November 7, 2019 at 2:46 am
Global Nanobots Market size is projected to reach USD 100 billion at a CAGR of 21% during the forecast period. The pathbreaking developments in robotics are expected to create favorable demand for ...
- New nanobots that ‘fly’ through the body could perform tiny surgerieson November 6, 2019 at 10:17 am
Researchers have developed nanobots that could perform small operations in the body and move around by flapping their wings. The Japanese art of origami has inspired many robotic designs, but ...
- Nanobots Swim Like Scallops In Non-Newtonian Fluidson November 4, 2019 at 4:00 pm
The idea of using nanobots to treat diseases has been around for years, though it has yet to be realized in any significant manner. Inspired by Purcell’s Scallop theorem, scientists from the Max ...
- Life without parole for war vet who said secret agency compelled him to kill stranger in Oceansideon October 22, 2019 at 5:14 pm
Agent Orange, Schmidt said, was the name of a secret government agency that had injected him with nanobots while he was a Marine. “That night, my nanobots were activated,” Schmidt testified.
- War veteran who said nanobots compelled him to kill stranger found legally saneon September 24, 2019 at 6:31 pm
It took a North County jury about five minutes to find that an Iraq war veteran was legally sane when he killed a stranger in 2017, rejecting his testimony that he believed that a secret agency had ...
- US Marine Combat Vet Talks of 'Agent Orange,' Nanobots, Head Injuries, PTSD in Murder Trialon September 17, 2019 at 3:16 pm
A U.S. Marine combat veteran who told police that he left his home two years ago hunting for someone to kill testified in his own defense Tuesday, describing a secret government agency "Agent Orange," ...
- How AI, IoT and nanobots can aid parasitic architecture in crowded citieson September 16, 2019 at 11:44 am
Aided by AI, the IoT, and nanobots, parasitic architecture presents an unconventional solution to crowded living spaces. We want the user to be his own house, by linking the robots to neuronal AI ...
- What are nanobots?on April 3, 2019 at 9:28 am
Nanobots à la Michael Crichton's Prey and other science fiction contraptions of nanoscale robots don't exist (yet). Not to be confused with these fictional nanorobots, for medical nanotechnology ...
- These injectable nanobots can walk around inside a human bodyon March 8, 2019 at 3:58 pm
Researchers have developed nanobots that can be injected using an ordinary hypodermic syringe, according to a new release. The nanobots are microscopic functioning robots with the ability to walk and ...
via Google News and Bing News