Lily Mortensen is advancing research at the leading edge of biomedicine, working on new ways to improve human health.

A materials science and engineering PhD student at the University of Colorado Boulder, Mortensen is investigating ways to combine 3D printing and ultrasound technology to benefit individuals suffering from certain medical conditions.

The eventual goal is to be able to inject a liquid polymer into the body and then use ultrasound frequencies to harden the material without cutting open the skin.

“Repairing a hole in the heart right now requires surgery,” Mortensen said. “What if you could inject something and repair it at a distance? Ultrasound is so cool because you can use it through a barrier like skin. Instead of cutting a patient open, we could inject a small amount of 3D printed material as a liquid and repair a defect in place.”

It is still very early research, but is the subject of investigation by scientists and engineers across the United States because of its great potential.

“We can choose polymers and components which are bio inert/compatible, so the body doesn’t attack it,” Mortensen said. “And the properties of ultrasound that make it good for noninvasive human examination, to see something under the skin, make it good for this too.”

It is still early research, with Mortensen testing various types of polymer inks and experimenting with the ultrasound parameters to determine the best compounds and intensities to cure the materials in place.

"It’s very hands-on. One of the issues I’m trying to solve is ultrasound printing has acoustic streaming, where the ultrasound force is so intense it causes the liquid to flow, but if it flows out of the area you want, that’s not giving us good resolution or focal size. We’ve made some progress, but it’s definitely difficult,” she said.

Mortensen utililizing ultrasound-induced polymerization to 3D print the ��������Ƶ Boulder Ralphie Logo through a clear barrier.

Working at the forefront of a research area presents unique challenges – notably that there is limited published research to fall back on.

“I’m building off other people's work, but branching into areas where I have to figure it out myself because nobody has figured it out yet,” she said.

Now in the third year of her PhD program, Mortensen did not always envision herself earning an advanced degree. After completing her bachelor’s in materials science at the University of Idaho, she found a job at a semiconductor company in upstate New York. It was engaging work, but Mortensen realized she wanted more.

“I learned a lot there, and I liked it, but I realized the work that I found really interesting was the research and development projects, and they were all handled by PhDs. So I applied to PhD programs,” she said.

She was drawn to ��������Ƶ Boulder by the variety of faculty research in the materials science program, the university’s culture, and the Rocky Mountains.

“Certain institutions are not known for treating their PhD students well. ��������Ƶ Boulder has a really good culture, and Boulder has great outdoor access and lots of interesting people,” she said.

Mortensen is currently finalizing her first research paper as lead author, on new types of inks that will enable ultrasound 3D printing of hydrogels. She is also hopeful her current work will lead to a patent application.

“This is a really cool technology, but there’s always the possibility it won’t work out,” she said. “That’s a chance with any research, but it’s where I want to be. Working in research and finding the next new thing.”

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