[Lindsay] has a wonderful writeup about a new toy in the shop, an ultrasonic transducer. The 28kHz, 70W bolt-clamped Langevin transducer by itself is not much use, you need a power supply ...

Inventions by African Americans into the 21st century include everything from toys to physics to aerospace technology.

It drives two ultrasonic transducers in parallel, and with them pointing towards each other and a bit of gap adjustment work it can successfully levitate pieces of polystyrene. There was some work ...

In this study, the research team developed an ultra-compact (1 mm²) transparent ultrasonic transducer capable of delivering high-resolution ultrasound and photoacoustic imaging simultaneously.