Engines are everywhere in our daily lives – from cars to washing machines. A futuristic field of science is working on tiny motors (Small motors take a big step forward) that can power a network of nano machines and replace some of the energy sources we use in devices today.
In new research published recently at ACS Nano, researchers at the Cockrell School of Engineering at the University of Texas at Austin have created the first solid-state optical nano motor. All previous versions of these light-driven engines live in some sort of solution that limits their capabilities to most real-world applications.
“Life started in water and eventually moved to land,” said Yuebing Zheng, an associate professor in Walker’s Department of Mechanical Engineering. “We’re making these micro-nano motors that always live in solution, operate in the ground, in the solid state.
” Researchers designed these engines to power various things. The rotary motion can capture dust and other particles, which is useful for measuring air quality. They can push the device to deliver the drug into the human body. And they can use small drones to track and measure, just like other minicars.
The new engine is less than 100 nanometers in diameter and can run on a solid substrate in low light. It can serve as a fuel-free and redundant engine to convert light into mechanical energy for various solid-state micro-/nano-electromechanical systems.
By bringing these nanomotors ashore and out of the water, we avoid, say, Brownian Motion, one of the biggest obstacles to implementing these devices. This happens when water molecules push these little motors out of their spin. The smaller the motor, the faster it will move. By removing the solution from the comparison side, you completely solve this problem.
Nanomotors are part of a large and growing field of small power sources. It serves as a halfway point between molecular motors on the small end and micromotors on the larger end.
This area is very important, but at the moment researchers are still trying to figure out the basic science to make these small engines more viable with increased efficiency. The reason scientists like to make these tiny motors is because they mimic some of the most important biological structures.
In nature, these motors control the distribution of cells and help them move. They work together and help organisms function. “Nanomotors help us safely control the nanoworld and create new things we want for our real world.” said Jingang Li, a postdoctoral fellow in Zheng’s group and lead author of the study.
By taking these motors out of the solution and putting them into chips, they have the potential to replace batteries multiple times, using only light to generate mechanical motion and power the device.
This collapse comes from a new design: a thin layer of material changes part of the substrate. A thin film can undergo a local and dynamic transformation from a solid to a quasi-liquid phase upon exposure to light. This phase change reduces the frictional force of the nanomotor and stimulates rotation.
This is the team’s first demonstration of engines using nanoparticles. In the future, researchers will continue to improve their creativity and work to improve performance by making them more robust and controllable, which will lead to the conversion of light into mechanical energy at higher speeds.
