Towards breath sensors that are self-powered by design
Bio-sensors implanted in the body are revolutionizing healthcare. How to power these sensors is an open challenge. One promising option is to harvest small amounts of energy from the body …
Tunable stiffness in fish robotics: mechanisms and advantages
When fish-like robots tune their stiffness in realtime, they can be much more efficient. Real fish use the same strategy. In this review article, we summarize the latest work on …
Tunable stiffness enables fast and efficient swimming in fish-like robots
Fish are thought to adjust their tail stiffness to swim efficiently over a wide range of speeds, but how they tune stiffness has been a mystery. We derived a model that combines fluid …
Influence of the ground, ceiling, and sidewall on micro-quadrotors
Because of their small size and agility, quadrotors could revolutionize search-and-rescue or terrain-mapping missions. However, to do so, they have to operate in confined spaces such as rubble corridors or …
How lovebirds maneuver through crosswinds in the dark
Pilots need complex instruments and training to safely fly through gusts when their vision is deprived. In contrast, birds fly reliably over open water and at night, despite being more …
How Micro Aerial Vehicles could exploit ground and ceiling effects
Micro Aerial Vehicles (MAVs) have the potential to revolutionize search-and-rescue, product delivery, aerial mapping, and weather sensing. Current models for how MAVs interact with solid boundaries are based on helicopters, …
Scaling laws for 3D pitching hydrofoils
Building on our previous work on 2-D pitching airfoils, we explored how forces and torques scale for 3-D pitching airfoils. The terms we added to existing theories were inspired by …
Adaptive control of turbulence intensity
We used a zero-finding algorithm to tune the turbulence intensity downstream of a grid of spinning vanes in a wind tunnel. We then explored how the algorithm was affected by …
The inverted glass harp
A traditional “glass harp” is an array of wine glasses filled to various depths. We discovered that a single empty wine glass submerged in a bath of water can also …
Optimizing the efficiency of flexible swimming panels
Simplified geometries can be used to isolate the effects of flexibility in swimming fish. Here we used an oscillating flexible rectangular panel to explore how efficiency is affected by frequency, …
Flexible panels produce more thrust near solid boundaries
We extended our work on rigid airfoils and discovered that flexible panels also produce more thrust near a solid boundary. This time, we checked swimming speed directly and confirmed that …
Scaling the efficiency of flexible swimming panels
Simplified geometries can be used to isolate the effects of flexibility in swimming fish. Here we used an oscillating flexible rectangular panel to explore how efficiency scales with panel stiffness …
An exact solution governing a nanofilm beneath an AFM probe
In Atomic Force Microscopy (AFM), tiny forces on a probe are used to map the fine-scale structure of a surface. We re-derived the forces on AFM probes for the special …