Sound could replace lasers in surgery

Moving from HOT to HAT, a dazzling new acoustic technology.

Sound could replace lasers in surgery
(Proceedings of the National Academy of Sciences)
  • Scientists announce the ability to simultaneously manipulate individual levitated objects.
  • Using high-frequency sound waves may provide a safer alternative to laser microsurgery.
  • Video of the research looks like a cartoon, but it's all real.

For a while now, scientists have presented demonstrations of sound's ability to levitate and move suspended particles. It's pretty cool stuff, and you can find lots of amazing videos showing intriguing patterns made with acoustic waves. Now, though, mechanical engineers Asier Marzo of Spain's Universidad Publica De Navarra and Bruce Drinkwater of the UK's University of Bristol have published research in which they demonstrate, for the first time, the ability to independently move particles in 3D space using ultrasonic sound waves. This technology has the potential to one day offer a less-invasive and destructive alternative to the lasers current employed in surgery suites. As Drinkwater tells University of Bristol News, "Optical tweezers are a fantastic technology, but always dangerously close to killing the cells being moved. With acoustics we're applying the same sort of forces but with way less energy associated. There's lots of applications that require cellular manipulation and acoustic systems are perfect for them."

HAT, not HOT

Marzo and Drinkwater call their invention "Holographic Acoustic Tweezers" (HOT), or simply "acoustic tweezers" in conversation. The HOT acronym differentiates the method from Holographic Optical Tweezers (HAT), the laser-based technology it hopes to supplant. The technique's medical applications do seem plausible: The scientists have already shown that they can connect polystyrene spheres with thread and use HAT to sew fabric.

Since moving polystyrene balls in the air is hardly the same as manipulating tiny objects in the body, the current breakthrough is seen as just a first step. Marzo and Drinkwater hope to demonstrate the system working in water in about a year, and from there move on to getting it going in biological tissue. Marzo says, "The flexibility of ultrasonic sound waves will allow us to operate at micrometre scales to position cells within 3D printed assemblies or living tissue. Or on a larger scale, to levitate tangible pixels that form a physical hologram in mid-air."

Working in the HAT array

Sergio Larripa, Asier Marzo, Bruce Drinkwater

How HAT works

Even in its current form, the HAT technology is impressive, to say the least.

"We applied a novel algorithm that controls an array of 256 small loudspeakers," says Marzo, "and that is what allows us to create the intricate, tweezer-like, acoustic fields." The speakers emit very high-frequency sound waves, in the 40 kHz range — human hearing is said to top out at just above 20 kHz, though there's some debate about its upper limits.

The HAT demonstration takes place inside a box-like array with the 256 single-centimeter speakers arranged on walls opposite each other over a reflective base. The "particles" they're moving are styrofoam balls from 1-3 millimeters in diameter, and HAT is currently capable of moving up to 25 of them at a time.

The future of HAT

Marzo describes his vision for HAT's future, saying, "The flexibility of ultrasonic sound waves will allow us to operate at micrometer scales to position cells within 3D printed assemblies or living tissue. Or on a larger scale, to levitate tangible pixels that form a physical hologram in mid-air." He describes another tantalizing use to Agencia Sync: "At micrometric scales," "Marzo says, it could allow "the manipulation of 3D cells to create structures beyond a simple culture in a two-dimensional Petri dish."

U.S. Navy controls inventions that claim to change "fabric of reality"

Inventions with revolutionary potential made by a mysterious aerospace engineer for the U.S. Navy come to light.

U.S. Navy ships

Credit: Getty Images
Surprising Science
  • U.S. Navy holds patents for enigmatic inventions by aerospace engineer Dr. Salvatore Pais.
  • Pais came up with technology that can "engineer" reality, devising an ultrafast craft, a fusion reactor, and more.
  • While mostly theoretical at this point, the inventions could transform energy, space, and military sectors.
Keep reading Show less

China's "artificial sun" sets new record for fusion power

China has reached a new record for nuclear fusion at 120 million degrees Celsius.

Credit: STR via Getty Images
Technology & Innovation

This article was originally published on our sister site, Freethink.

China wants to build a mini-star on Earth and house it in a reactor. Many teams across the globe have this same bold goal --- which would create unlimited clean energy via nuclear fusion.

But according to Chinese state media, New Atlas reports, the team at the Experimental Advanced Superconducting Tokamak (EAST) has set a new world record: temperatures of 120 million degrees Celsius for 101 seconds.

Yeah, that's hot. So what? Nuclear fusion reactions require an insane amount of heat and pressure --- a temperature environment similar to the sun, which is approximately 150 million degrees C.

If scientists can essentially build a sun on Earth, they can create endless energy by mimicking how the sun does it.

If scientists can essentially build a sun on Earth, they can create endless energy by mimicking how the sun does it. In nuclear fusion, the extreme heat and pressure create a plasma. Then, within that plasma, two or more hydrogen nuclei crash together, merge into a heavier atom, and release a ton of energy in the process.

Nuclear fusion milestones: The team at EAST built a giant metal torus (similar in shape to a giant donut) with a series of magnetic coils. The coils hold hot plasma where the reactions occur. They've reached many milestones along the way.

According to New Atlas, in 2016, the scientists at EAST could heat hydrogen plasma to roughly 50 million degrees C for 102 seconds. Two years later, they reached 100 million degrees for 10 seconds.

The temperatures are impressive, but the short reaction times, and lack of pressure are another obstacle. Fusion is simple for the sun, because stars are massive and gravity provides even pressure all over the surface. The pressure squeezes hydrogen gas in the sun's core so immensely that several nuclei combine to form one atom, releasing energy.

But on Earth, we have to supply all of the pressure to keep the reaction going, and it has to be perfectly even. It's hard to do this for any length of time, and it uses a ton of energy. So the reactions usually fizzle out in minutes or seconds.

Still, the latest record of 120 million degrees and 101 seconds is one more step toward sustaining longer and hotter reactions.

Why does this matter? No one denies that humankind needs a clean, unlimited source of energy.

We all recognize that oil and gas are limited resources. But even wind and solar power --- renewable energies --- are fundamentally limited. They are dependent upon a breezy day or a cloudless sky, which we can't always count on.

Nuclear fusion is clean, safe, and environmentally sustainable --- its fuel is a nearly limitless resource since it is simply hydrogen (which can be easily made from water).

With each new milestone, we are creeping closer and closer to a breakthrough for unlimited, clean energy.

The science of sex, love, attraction, and obsession

The symbol for love is the heart, but the brain may be more accurate.

Videos
  • How love makes us feel can only be defined on an individual basis, but what it does to the body, specifically the brain, is now less abstract thanks to science.
  • One of the problems with early-stage attraction, according to anthropologist Helen Fisher, is that it activates parts of the brain that are linked to drive, craving, obsession, and motivation, while other regions that deal with decision-making shut down.
  • Dr. Fisher, professor Ted Fischer, and psychiatrist Gail Saltz explain the different types of love, explore the neuroscience of love and attraction, and share tips for sustaining relationships that are healthy and mutually beneficial.

Sex & Relationships

There never was a male fertility crisis

A new study suggests that reports of the impending infertility of the human male are greatly exaggerated.

Quantcast