As we look ahead to the Schmidt Science Fellows Interdisciplinary Science Summit 2025, held in association with Caltech in Pasadena, it’s the perfect moment to spotlight the research of our 2024 Schmidt Science Fellow, Peter Serles. 

Peter’s Fellowship Placement is hosted by Julia Greer in Caltech’s Division of Engineering and Applied Science. He exemplifies the spirit of interdisciplinary science, which is at the heart of our community.

By combining expertise in mechanical engineering, biomedical science, and advanced manufacturing, he is opening up new possibilities at the frontiers of medical science.

Designing Materials of the Future to Advance Stem Cell–Based Brain Models

Imagine being able to speed up the innovation of new materials that nature has not yet revealed.

Well, we don’t have to imagine: a project that combines machine learning, mechanical engineering, and nano-3D printing is helping us to accelerate the process.

This project, led by 2024 Fellow Peter Serles, resulted in the development of an incredible material that is as strong as steel but as light as Styrofoam.

As a Schmidt Science Fellow, Peter is now applying similar nano-3D printing technologies to create a miniature device that mimics blood vessels, supporting the growth of brain tissue from stem cells.

This advancement could significantly improve brain disease modeling and fast-track clinical drug trials.

Peter has always been fascinated by how the look, feel, and function of materials are shaped by their basic elements, from the atomic arrangement to the structural shapes.

“One of the hardest problems in materials science is to create a material that is both high-performance and lightweight,” he explains.

During his PhD at the University of Toronto, Peter teamed up with experts in machine learning from the Korea Advanced Institute of Science and Technology (KAIST) to explore nanoscale geometries that don’t yet exist in the natural world.

With machine learning algorithms informed by mechanical simulations, the team explored the mechanical performance of hundreds of different shapes.

“Many of the geometries produced materials with worse properties than the control, yet the machine learning used this to predict entirely new geometries which produce much stronger and lighter materials,” says Peter.

Working with materials scientists and chemical engineers, the team simulated the mechanical properties of the new nano-geometries.

“We were blown away by what we found,” says Peter, “By just rearranging where the material is distributed, we more than doubled the strength of the material without adding any weight, to create something as strong as steel but as light as foam.”

Next, in collaboration with a team of optics engineers at the Karlsruhe Institute of Technology, Germany, the team printed nearly 20 million nano-lattices together to produce a 10mm piece of the new super-strong lightweight material.

“It was such a weird experience to hold something so light in your hand, but so strong you couldn’t break it,” says Peter, whose findings were published in Advanced Materials.

Scaling up to full production may take another decade, but the potential impact is huge. These materials could transform aerospace, defense, and automotive, helping to create super-lightweight aircraft, spacecraft, and cars, with significant benefits in fuel efficiency and reduced climate impact.

Crossing disciplinary boundaries was key to Peter’s PhD success and inspired his 2024 Schmidt Science Fellows project.

Working under Julia Greer, an expert in mechanical and materials engineering at California Institute of Technology and Giorgia Quadrato, a world leader in stem cell research at the University of Southern California, Peter is now combining nano design, 3D printing, and stem cell engineering to help transform medical science.

Human stem cells can be grown into clusters of brain tissue called organoids, which offer huge opportunities for studying brain development and disease, but current techniques can only grow very small, immature tissue samples.

“Right now, the cells don’t have veins running through them, so the tissue in the center starts to die when it doesn’t receive nutrients,” explains Peter.

Using nano design and 3D printing, Peter and his team are creating a microfluidic artificial vascular support system to maintain tissue health and grow larger and more mature brain tissue samples.

Creating this human-specific brain tissue would be a major leap forward for drug screening, enabling hundreds of target drugs to be tested at once on near-identical human brain tissue samples instead of a colony of mice, with the potential to knock years off drug discovery timelines.

Being able to grow more mature brain tissue will also enable scientists to study disease progression and neurodevelopment and could even open the opportunity to grow replacement organs in the future.

“The Schmidt Science Fellowship has given me the opportunity to dream big and do the most impactful things with my research,” says Peter.

Having not touched biology since grade 10, the Fellowship allowed him to take a risk and pivot into a new field.

“Learning about stem cell biology and neuroscience has been a mountain to climb, but I feel so fortunate to come in every day and work on what I feel to be the most exciting, impactful, and cool science.”

Peter is one of seven Fellows to pursue their Fellowship Research Placement at Caltech since 2018.