Each year, more than 2 million people around the world undertake heart surgery, ranging from minimally invasive procedures to operations that require cracking open the rib cage to access the heart itself.
Many of these life-saving procedures require stopping the patient’s heart and using a heart-lung bypass machine to keep the blood flowing, while surgeons repair damaged valves, ventricles, and aortae.
While the heart can begin pumping by itself after the procedure, sometimes it needs a kickstart, and that can be a challenge for a variety of reasons. That’s where UChicago Pritzker School of Molecular Engineering PhD candidate Pengju Li’s work aims to make a difference. Li is the first author of a paper published in Nature about a new material solution to this problem.
He is part of an impressively interdisciplinary group of UChicago researchers in the Tian Lab that has created a new silicon-based device – a thin film 100 times lighter than facial tissue – to restart and control heartbeats with the gentle flashing of light. The group also has invented a new, minimally invasive endoscopic procedure to apply the device to the heart’s surface.
“Pengju has innovated a method using physical chemistry measurement techniques to visualize photoelectrochemical current dynamics over a device surface through a patch clamp setup,” said UChicago Chemistry Prof. Bozhi Tian. “Traditionally used by neuroscientists for electrophysiology, Pengju's adaptation of this precise tool for 3D materials property mapping is a breakthrough.”
Breaking down silos
Li undertook his undergraduate degree in Singapore. There his research focused on developing skin prostheses for amputees. This was his introduction to the integration of engineered materials and the human body.
Wanting to delve more deeply into this area, he chose the Pritzker School of Molecular Engineering at UChicago for his graduate work. Through PME’s unique interdisciplinary approach, Li was able to enhance his engineering background with new expertise in chemistry, nanofabrication, electronics, medicine, and other areas siloed off from each other in a traditional university structure.
“At PME, people with diverse backgrounds can gather together and achieve great things,” Li said.
Even Li’s position – a Pritzker Molecular Engineering graduate student in a Department of Chemistry lab – reflects this interdisciplinary approach.
Similarly, Li’s coauthors on the Nature paper come from across the UChicago community, including the James Franck Institute, the Department of Chemistry, and the Department of Surgery.
“I work with PME colleagues, I work with the Physical Sciences Division and the Biological Sciences Division – the collaborations are critical to the work we do,” said Li.
Last year, Li was honored with both the Grier Prize for Innovative Research in the Biophysical Sciences and a Harper Dissertation Fellowship for his research contribution across multiple disciplines.
Finding inspiration in nature
Many of Li’s insights come not in the lab but in the wild. An avid hiker and stargazer, he recently trekked North Cascades National Park in Washington state.
“Natural beauty stimulates my mind and helps inspire new ideas for my research,” Li said, “The adaptability of living organisms in nature inspires me to think about more dynamic devices for use in biomedical research.”
Photography – whether of a starry night in the Cascades or through the lens of a scanning electron microscope – is another fixture of Li’s process. In 2023, his photography took first place in the James Franck Institute Image Contest and second place in the UChicago Science as Art competition. He was also named one of three winners of the Pritzker Nanofabrication Facility’s yearly PANIC! photography contest.
He maintains a gallery of his photography at @nanoscale_ on Instagram.
Li is also an active student mentor, working with six UChicago undergraduate and graduate students from different disciplines over his four years at PME. He said this helps underpin the interdisciplinary atmosphere at UChicago engineering that makes innovative research possible. Recently Li has been honored with the Honorable Mention in the Maria Lastra Mentoring Award presented by PME.
“It’s the merging of two minds in order to merge two different fields,” Li said. “They have their own training and their own different backgrounds. I have my training and my own background. I really enjoy the collaborative process and the impactful outcomes.”
Learn more about the research behind the paper