Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Why Inkjet Paper Curls
Printed pages from inkjet printers tends to curl up over time. Researchers found that this long-term curl correlates with the migration of glycerol — one of the solvents used in inkjet ink — through the paper’s fiber layers toward the unprinted side. The glycerol migration makes the cellulose fibers in the paper swell up, causing…
Bubbles Encased in Ice
If you’ve ever made ice in a freezer, you’ve probably noticed the streaks of frozen bubbles inside the ice. In its liquid state, water is good at dissolving various gases — like the carbon dioxide in sparkling water. During freezing, though, those gases cannot remain in solution; the water simply doesn’t have space between its…
How Moths Confuse Bats
When your predators use echolocation to locate you, it pays to have an ultrasonic deterrence. So, many species of ermine moths have structures on their wings known as tymbals. These areas have a band of ridges, and, when the moth’s wing lifts or falls, the ridges buckle one-by-one. A nearby bald patch on the wing…
Drops of Fiber Suspensions
To 3D print with fiber-infused liquids, we need to understand how these drops form, break-up, and splash. That’s the subject of this research poster, which shows drops of a fiber suspension forming and pinching off along the top of the image. In the lower half of the image, drops of the suspension hit a hydrophilic…
“Ferro Field”
Ferrofluid forms a labyrinth of blobs and lines against a white background in this award-winning photo by Jack Margerison. Ferrofluids are a magnetically-sensitive fluid, typically created by suspending magnetic nanoparticles in oil. Depending on the ferrofluid’s surroundings that and the applied magnetic field, all sorts of patterns are possible from spiky crowns to wild mazes.…
Floating in Sync
Objects on a vibrating liquid bath can interact with each other through the waves they make as they bounce. Here, researchers look at three-armed spinners interacting in pairs and in larger groups. A pair of spinners can synchronize so that they spin together or so that they spin in opposing phases. With more spinners, more…
Mimicking Plant Movement
Many plants control the curvature of their leaves by selectively pumping water into cells that line the outer surface. This swelling triggers bending. Engineers created their own version of this structure by 3D-printing trapezoidal shapes onto a fabric. Then, they heat sealed a second layer of fabric over this, creating airtight channels. When inflated, these…
The Channel Tunnel
To celebrate the 30th anniversary of the Channel Tunnel, Practical Engineering takes a look back at the construction and operation of this incredible piece of infrastructure. This 30-mile-long underwater tunnel began construction in the 1980s, using giant Tunnel Boring Machines to drill out three tunnels, starting from either side and, incredibly, meeting in the middle.…
Reapproaching Supersonic Air Travel
Before the Concorde even began regular flights, protests over its sound levels caused the U.S. and many other countries to ban overland commercial supersonic flight. Those restrictions have stood for fifty years. But NASA and Lockheed Martin Aeronautics are hoping to make supersonic air travel a possibility again with their experimental X-59 aircraft, designed to…
“Color Show”
Brightly colored paints and inks mix and flow in artist Roman De Giuli’s “Color Show.” De Giuli typically creates this fluid art in thin layers atop paper. He’s a master of the form, manipulating surface tension gradients to create streaming flows, dendritic patterns, and feathery wisps. If this kind of art is your jam, he…