Freaky Fluids

At the center of a giant hourglass, a metallic skull with gaping jaws hangs above a bowl of glistening black fluid. Suddenly, the liquid seems to come alive. Quivering dark tendrils reach upward from the bowl into the skull’s open jaws. The fluid gathers into a twisting ball of spikes inside the skull’s mouth. Then the movement stops, and the fluid drains back down in thick black streams.

This unnerving sculpture, called Killing Time, is the work of the artist Mesplé, who’s based in Los Angeles, California. For 12 years, Mesplé has created mesmerizing pieces of art, like this one, that incorporate ferrofluids. These inky black substances contain billions of tiny magnetic particles suspended in a liquid (see Fluid Components). Ferrofluids respond to a magnetic field—making them perfect for Mesplé’s dynamic and eerie shape-shifting sculptures.

A metallic skull with wide open jaws hangs at the center of a giant hourglass. A bowl of shiny black fluid sits below the skull. Suddenly, the liquid seems to come alive. Dark strings of fluid quiver and reach upward from the bowl into the skull’s open jaws. The fluid gathers inside the skull’s mouth. It forms a twisting ball of spikes. Then the movement stops, and the fluid falls back down in thick black streams.

This chilling sculpture is called Killing Time. It’s the work of the artist Mesplé in Los Angeles, California. For 12 years, Mesplé has created fascinating pieces of art, like this one. They contain ferrofluids. These inky black liquids hold billions of tiny magnetic particles (see Fluid Components). Ferrofluids respond to a magnetic field. That makes them perfect for Mesplé’s moving and eerie shape-shifting sculptures.

Ferrofluids were developed by NASA in the 1960s. The space agency wanted a way to move liquid fuel through a rocket in space, in the absence of Earth’s gravitational pull. They proposed a liquid that could be controlled with magnets. NASA eventually shifted its focus from liquid to solid fuels, so ferrofluids never took off. But engineers have found many other uses for them.

For example, a magnetic field holds ferrofluid in place around the spinning center of a computer’s hard drive, which stores data. The fluid prevents debris from getting into the drive’s interior, which could cause it to malfunction. Ferrofluids are also used in audio technology and aviation, and researchers are exploring possible applications in medicine and astronomy.

Scientists have discovered that in the presence of a magnet, a ferrofluid’s surface forms spikes. “The shapes result from the balance of forces acting on the fluid,” says Isaac Torres Díaz, a chemical engineer at the University of Alabama in Huntsville who studies magnetic fluids. One of those forces is surface tension, resulting from attraction among molecules at the fluid’s surface. Then there’s the magnetic force, which pushes and pulls on particles in the fluid. Together, they cause sharp peaks to jut out from its surface.

NASA developed ferrofluids in the 1960s. The space agency wanted to move liquid fuel through a rocket in space, without help from Earth’s gravitational pull. They proposed a liquid that magnets could control. Later, NASA changed its focus from liquid to solid fuels, so ferrofluids never took off. But engineers have found many other uses for them. 

For example, ferrofluid is used in a computer’s hard drive, which stores data. A magnetic field holds the fluid in place around the drive’s spinning center. The fluid stops debris from getting inside, which could cause the drive to fail. Ferrofluids are also used in audio technology and aviation. And researchers are studying ways to use them in medicine and astronomy. 

Scientists found that a ferrofluid’s surface forms spikes when a magnet is near. “The shapes result from the balance of forces acting on the fluid,” says chemical engineer Isaac Torres Díaz. He studies magnetic fluids at the University of Alabama in Huntsville. One of those forces is surface tension. It comes from attraction among molecules at the fluid’s surface. Then there’s the magnetic force. It pushes and pulls on particles in the fluid. Together, they cause sharp peaks to jut from its surface.

Mesplé studied art, computer science, and engineering in graduate school. He first came across ferrofluids in a scientific article. “It was so beautiful and alien-looking,” he says. “I knew I wanted to do something with it.”

“Usually, my work starts with thinking about how cool it would be if I could make a certain thing happen,” says Mesplé. “Then I’m problem-solving and figuring out what works and what doesn’t. I fail a ton before I’m successful.”

Mesplé’s first magnetic sculpture was a sphere resting in a pool of ferrofluid. Sensors in the piece detect when a person approaches. A computer program uses data from the sensors to control the movement of a magnet inside the sphere. The magnet follows the viewer as they move, causing a spiky ball of ferrofluid to glide around the sphere’s exterior. Early versions of the artwork had some kinks to work out: “The magnet would pick up too much fluid and throw the stuff everywhere,” says Mesplé. “I adjusted the computer programming to have the magnet shake off some fluid at the bottom and move up the sphere more slowly.”

Mesplé studied art, computer science, and engineering in graduate school. He first saw ferrofluids in a scientific article. “It was so beautiful and alien-looking,” he says. “I knew I wanted to do something with it.”

“Usually, my work starts with thinking about how cool it would be if I could make a certain thing happen,” says Mesplé. “Then I’m problem-solving and figuring out what works and what doesn’t. I fail a ton before I’m successful.”

Mesplé’s first magnetic sculpture was a sphere in a pool of ferrofluid. The piece has sensors to detect when a person approaches. The sensors send data to a computer program, which moves a magnet inside the sphere. When the person moves, the magnet follows. It causes a spiky ball of ferrofluid to slide around the outside of the sphere. Early forms of the artwork had some problems. “The magnet would pick up too much fluid and throw the stuff everywhere,” says Mesplé. “I adjusted the computer programming to have the magnet shake off some fluid at the bottom and move up the sphere more slowly.”

Another piece Mesplé created was a wall with ferrofluid flowing down it. The wall was dotted with 320 electromagnets, which consist of wire coiled around a metal core. Running an electric current through the wire produces a magnetic field. By controlling the flow of electricity, a person can turn an electromagnet on and off or adjust its strength. Ordinary magnets can’t be fine-tuned this way.

Sensors in the wall sculpture detected the shape and movement of an observer and activated a corresponding pattern of electromagnets. That created a moving silhouette of the viewer made out of spiky ferrofluid. Initially Mesplé used an aquarium pump to keep ferrofluid flowing over the wall. “But fluid kept gumming up the pump, and it kept burning out,” he says. Soon he realized that the pump contained a magnet that attracted the fluid, which explained why it kept getting stuck. Mesplé later adapted the concept, changing the wall into a pool of ferrofluid a viewer could look down into, eliminating the pump problem (see Magnetic Pool).

Mesplé also created a wall with ferrofluid flowing down it. The wall was dotted with 320 electromagnets. These are made of wire coiled around a metal core. If you run an electric current through the wire, it produces a magnetic field. A person controls the flow of electricity to turn the electromagnet on and off or adjust its strength. Regular magnets can’t be fine-tuned like this.

Sensors in the wall sculpture detected the shape and movement of a viewer. Then the sensors turned on electromagnets in the same pattern. That created a moving image of the viewer made from spiky ferrofluid. At first, Mesplé used an aquarium pump to keep ferrofluid flowing over the wall. “But fluid kept gumming up the pump, and it kept burning out,” he says. Soon he realized that the pump contained a magnet, and it attracted the fluid. That’s why the pump kept getting stuck. Mesplé later adjusted the idea. Instead of the wall, he created a pool of ferrofluid. A viewer could look down into it. That got rid of the pump problem (see Magnetic Pool).

Mesplé wondered what other tricks he could get ferrofluid to perform. For example, could he make it jump across a gap? That question led to Killing Time, the ferrofluid-slurping skull. “It requires a tremendously powerful magnet,” he says. Off-the-shelf electromagnets weren’t strong enough, so Mesplé built his own.

Strong electromagnets get really hot, though. At first Mesplé used fans to cool the magnet. But during an art show, he realized he needed something better. “The piece had been running all day,” he recalls. That’s when a young attendee turned to him and asked, “How do you think the artist got it to smoke like that?” Thankfully, nothing was actually burning: The “smoke” was vapor released as one of the warm fluid’s ingredients evaporated from a liquid to a gas. But to be on the safe side, Mesplé built a system that circulates coolant through the sculpture.

Despite the constant challenges, “it’s amazing to be able to dream up something new,” says Mesplé. And he loves seeing people react to his work: “It’s fascinating to show off how amazing physics is in a way that most people have never seen before.”

Mesplé wondered: What other tricks could he do with ferrofluid? For example, could he make it jump across a gap? That question led to Killing Time, the ferrofluid-drinking skull. “It requires a tremendously powerful magnet,” he says. Off-the-shelf electromagnets weren’t strong enough, so Mesplé built his own.

But strong electromagnets get really hot. At first, Mesplé used fans to cool the magnet. He realized he needed something better during an art show. “The piece had been running all day,” he says. Then a young viewer turned to him and asked, “How do you think the artist got it to smoke like that?” Thankfully, nothing was really burning. One of the warm fluid’s ingredients was evaporating from a liquid to a gas. It released vapor that looked like smoke. But Mesplé wanted to be on the safe side. So he built a system that moves coolant through the sculpture.

Mesplé’s work involves constant challenges. But he says that “it’s amazing to be able to dream up something new.” And he loves to see people react to his work. “It’s fascinating to show off how amazing physics is in a way that most people have never seen before.”