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June 15, 2017

ASU scientists develop technique using tiny crystal 'time capsules' to trace pulses of heat inside a volcano; may help better predict risk

Volcanos that erupt explosively are the most dangerous in the world. When they blow, they eject giant clouds of hot ash mixed with gases at temperatures up to 2,000 degrees Fahrenheit that engulf everything in their way. 

A new technique developed by Arizona State University scientists, working with colleagues in California, Oregon, Michigan, Singapore and New Zealand, lets scientists track the heating history of the molten rock, or magma, that feeds explosive volcanos. The technique uses tiny crystals of zircon that form within the magma. 

The picture coming from the new research, published June 16 in the journal Science, suggests that pulses of heat in the magma before a volcanic eruption both begin and end more abruptly than scientists previously thought. Moreover, the heat pulses last a shorter time than expected. 

The new findings will change how scientists view the internal workings of all volcanos, and it may help them gain a better idea when an active volcano poses the most risk.

The team gathered debris that erupted from New Zealand's Mount Tarawera about 700 years ago. That eruption, roughly five times the size of the 1980 Mount St. Helens eruption, brought to the surface magma that recorded the volcano's thermal history, including the heat pulses leading up to the eruption.

Tiny bits tell a tale

The magma contained zircon crystals, each less than a millimeter long, which were the focus for the ASU scientists on the team. 

"For the first time, we can tell how long ago a given zircon crystal formed — and we can also measure how many heat pulses it has experienced," said geochemist Christy Till, assistant professor in ASU's School of Earth and Space Exploration. She is a co-author of the Science paper. 

"In addition," Till explained, "we can tell how hot those pulses were and how fast the crystals cooled after each of them." This lets geo-scientists build a detailed heat timetable of a volcano's past activity, including what occurred long before any historical records.

"We were especially interested in what events lead up to an eruption," Till said. "To our surprise, we discovered that these zircon crystals are telling us that they mostly led a very sedate, boring life."

The zircon crystals from Mount Tarawera had formed at least tens of thousands of years ago inside the volcano, as molten rock cooled, Till said. "Over their lifespan, they experienced only a few brief heating events, whereas we had expected to see more prolonged pulses of heating."

The secret to the new findings is an advanced mass spectrometer at ASU, one of a small handful of similar instruments in the United States. 

"The key to tracing the thermal history of these crystals is our NanoSIMS instrument," said ASU Research Assistant Professor Maitrayee Bose, who will join the School of Earth and Space Exploration faculty in August. The "SIMS" in the name stands for Secondary Ion Mass Spectrometry, and the "nano" part underscores that it works on very small scales.

As Bose said, "In essence, the NanoSIMS is a highly complex microscope that gives precise information about the elemental and isotopic composition of samples no wider than the width of a human hair." This extreme resolution let the scientists trace successive heat pulses that left marks in the crystals like tree rings.

How does push become bang?

Although the discovery involves microscopic-sized crystals, the results will likely have a large effect on the field of volcanology.

"Our idea of how the magma reservoir below a volcano behaves has evolved a lot over the last 10 or 15 years," Till said.

"It's no longer seen as a big blob of magma that resides below a volcano," Till explained. "Instead, these magma bodies are the result of many smaller injections of very hot magma into a cooler mush of crystals and older magma that lies in the shallower parts of the volcano's interior."

Yet how these injections combine to make an eruption is a matter still to be understood, Till said. As scientists track how heat pulses cool off and magma turns mostly into solid crystals, a basic question keeps returning: What causes a volcano to erupt? 

"It's a process we don't really understand yet," Till said. "Maybe a very large pulse of magma triggers the volcano to blow, or it could be more complicated. Maybe there's another process in which the magma cools off, forms crystals — and out of the still-hot residue, bubbles of gas form which causes the eruption.

"We simply don't know yet."

 

Top photo: New Zealand's Mount Tarawera volcano has erupted many times. Here an outburst in 1886 broke open a dome of rhyolite rock built by an eruption about 700 years ago. This open rift let the scientists collect tiny zircon crystals from the earlier eruption's debris, visible as outcrops of white-toned rock. Photo by Kari Cooper

Robert Burnham

Science writer , School of Earth and Space Exploration

480-458-8207

 
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ASU students team up with Barrow to create medical rehab devices

ASU students create 3 solutions to help those with impaired mobility.
Entrepreneurship-based class teaches how to move devices out of lab, into world.
June 16, 2017

Therapists and physicians share challenges; engineering professor's class develops solutions, 3 of which are being patented

In most classes, a good job results in an "A."

In Panagiotis Polygerinos’ mechatronics device class, a good job results in a patented invention that improves lives.

The Arizona State University assistant professor (pictured above) teamed his engineering students with therapists and physicians at Barrow Neurological Institute in Phoenix to create medical rehab devices.

Three of those devices are being patented.

“Now we have three provisional patents, we’re about to submit for a full application, we have three papers submitted, and who know what else will come?” Polygerinos said.

The class — EGR 598 Mechatronics Device Innovation — is entrepreneurship-based. Students learn how to move their inventions out of the lab and into the world as well as create them.

“The course is about how do you build a device from scratch?” Polygerinos said. “It takes a lot, but it’s worth it.”

Barrow medical professionals came up with about 15 ideas. The class chose three of them and went to work.

Video: See the Soft Robotic Back Orthosis in action.

After back surgery or recovering from a back injury, patients currently have to wear splints.

Splints result in “pressure points, fatigue to the skin, inability to perform in your everyday life because you are restricted,” Polygerinos said. “Now the idea was, can we create a device that is transparent to the user?”

The Soft Robotic Back Orthosis is a variably adjusting device, a network of webbing, straps and soft inflatable bladders that transmits loads and forces around. It protects the back and prevents wearers from movements that would aggravate their injuries.

Video: See how the Soft Robotic Shoulder Assist Device for Wheelchair Users works.

Patients who use wheelchairs develop shoulder pain from repetitively pushing the wheels. The Soft Robotic Shoulder Assist Device for Wheelchair Users gives a boost in pushing at the exact second it is most difficult. Results from experiments with a wheelchair test participant were promising.

People who use walkers tend to lean on them too much, contorting their backs and arms. Handles on the Biofeedback Walker vibrate when users put too much pressure on them. It’s a way of having a physical therapist constantly present, correcting their posture. Students are still developing the walker.

The three teams of four graduate students each were funded by a $2,500 budget from Venturewell, a nonprofit that funds and trains faculty and student innovators to create successful, socially beneficial businesses.

Arizona Technology Enterprises, ASU’s intellectual property management company, prepped students on how to bring inventions to market, providing lectures on intellectual property, marketing, licensing and startups.

As well as creating, designing, prototyping and evaluating, students have to write a publication-quality paper and submit it to a conference or journal.

“They have to submit a paper — not to me, that I would put in a drawer after I give them a grade — but they have to submit a paper at a conference,” Polygerinos said.

Instead of only working in the lab, Polygerinos wants to recruit and work with actual patients, to test devices on them, collect more data and prove prototypes work.

The course will be offered again in January 2018.

Projects don’t necessarily need to end with the course, Polygerinos said.

“If they are willing to continue, why not? I am here to help them to completion if they want and to make an impact on the real world,” he said.

 

Top photo: ASU Assistant Professor Panagiotis Polygerinos demonstrates the Soft Robotic Back Orthosis device as he talks about innovative medical habilitation devices his graduate students at the Polytechnic campus' Ira A. Fulton Schools of Engineering created with the assistance of physicians and clinicians at the Barrow Neurological Institute, with support from VentureWell and AzTE. Photo by Charlie Leight/ASU Now

Scott Seckel

Reporter , ASU Now

480-727-4502