Video: New Liquid Pistons Made of Magnetic Droplets Could Power Self-Focusing Lenses | Popular Science

Video: New Liquid Pistons Made of Magnetic Droplets Could Power Self-Focusing Lenses | Popular Science: Researchers at Rensselaer Polytechnic Institute embedded drops of ferrofluid, a liquid infused with magnetic nanoparticles, into a thin substrate that was submerged in water. Then they exposed the device to a magnetic field to make one of the droplets vibrate back and forth (up or down in the image above), which caused its partner to oscillate in a mirror pattern. This ballet displaces teeny amounts of liquid, moving it from one chamber to another, according to Amir H. Hirsa, a mechanical engineering professor at Rensselaer. The piston is superfast, allowing micro-scale devices with cycling speeds in the kilohertz range.