One day, deformable microrobots could be a toothbrush, mouthwash and floss all in one. Developed by a multidisciplinary team at the University of Pennsylvania, the technology promises to provide a new automated way to perform mundane but critical oral care tasks such as brushing and flossing.
These microrobots consist of iron oxide nanoparticles with catalytic properties and magnetic activity. Using magnetic fields, researchers can direct the movement and configuration of particles to create bristle-like structures that sweep away plaque from the broad surfaces of teeth, or to form thin threads that slide between teeth like dental floss. In both cases, a catalytic reaction drives the nanoparticles to produce antibacterial agents that directly kill harmful bacteria in the mouth.
Routine oral care is cumbersome, experts say, as you have to brush, floss, and rinse your mouth, a manual, multi-step process. The biggest innovation here is that the robotic system can do all 3 processes in a single, hands-free, automated way.
Geckos are known for their exceptional grip on their feet, a "superpower" that comes from a sophisticated set of sticky structures on the skin on their toes: extremely fine and dense bristles. Using a synchrotron microscope, the National Institute of Standards and Technology analyzed the surface structure of the bristles using high-energy X-rays and found that they were surrounded by an ultra-thin film of water-repellent lipid molecules 1 nanometer thick.
Lipids are small hydrophobic molecules that push away any moisture beneath the bristles, allowing them to come into closer contact with surfaces and help the gecko maintain its grip on wet surfaces. The bristles themselves are made of keratin, similar to the keratin in human hair and nails. Research has shown that keratin fibers line up in the direction of the bristles, which may help them resist abrasion.
The bristles on the gecko's toes are flexible, with their ends in close contact with the climbing surface, and electrons in the two materials interact, creating an attractive force known as the van der Waals force. When the foot needs to be moved, the gecko changes the angle of the bristles, interrupting the van der Waals force to take the next step.
Many products are inspired by the grip of gecko toes, including tapes with bristle-like microstructures.
