When you blow air across the neck of a bottle, you're not just producing a pleasant tone: you're also demonstrating a phenomenon called Helmholtz resonance. This occurs when airflow passing across an opening causes air trapped inside a cavity (like a glass bottle) to oscillate back and forth. At certain frequencies, these oscillations become much stronger, producing the familiar humming sound. Now, researchers in the MicroBioRobotic Systems ( MICROBS) Lab in EPFL's School of Engineering have harnessed the physics behind this phenomenon to build hollow structures that act as miniature, sound-powered machines. The innovation has been published in Science Advances.

These new'microfliers' could help engineers build miniature vehicles that don't require batteries or engines. More information Adding us as a Preferred Source in Google by using this link indicates that you would like to see more of our content in Google News results. The MICROBS Lab's microfliers compared with a 2015 Swiss 5 Rappen coin, which are only about half and inch in diameter. Breakthroughs, discoveries, and DIY tips sent six days a week. By signing up, you confirm you are 16+, will receive newsletters and promotional content and agree to our Terms of Use and acknowledge the data practices in our Privacy Policy .

Scientists at the University of Washington have developed flying robots that change shape in mid-air, all without batteries, as originally published in the research journal Science Robotics. These miniature Transformers snap into a folded position during flight to stabilize descent. They weigh just 400 milligrams and feature an on-board battery-free actuator complete with a solar power-harvesting circuit. These robots actually mimic the flight of different leaf types in mid-air once they're dropped from a drone at an approximate height of 130 feet. The origami-inspired design allows them to transform quickly from an unfolded to a folded state, a process that takes just 25 milliseconds.

Researchers at the University of Washington developed small robotic devices that can change how they move through the air by "snapping" into a folded position during their descent. Shown here is a timelapse photo of the "microflier" falling in its unfolded state, which makes it tumble chaotically and spread outward in the wind. On a cool afternoon at the heart of the University of Washington's campus, autumn, for a few fleeting moments, appears to have arrived early. Tiny golden squares resembling leaves flutter then fall, switching from a frenzied tumble to a graceful descent with a snap. Aptly named "microfliers" and inspired by Miura-fold origami, these small robotic devices can fold closed during their descent after being dropped from a drone.