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Researchers in McGill’s Department of Mechanical Engineering have discovered a safe and low-cost method of engineering living materials such as tissues, organs and blood clots. By simply vibrating these materials as they form, scientists can dramatically influence how strong or, weak they become.

The findings, published in the journal Advanced Functional Materials, could have a range of innovative applications, including in organ transplants, wound healing and regenerative medicine.

Good vibrations

The researchers used a speaker to apply controlled vibration, gently agitating the living materials during formation. By doing so, they found they could influence how cells organized and how strong or weak the final material became.

The technique works across a range of soft cellular materials, including blood clots made from real blood and other human tissues.

Aram Bahmani, study co-author and Yale postdoctoral fellow, conducted the research at McGill as a PhD student with Associate Professor Jianyu Li’s Biomaterials Engineering lab. Bahmani explained that strong, fast-forming blood clots are vital for use in emergencies like traumatic injuries. They’re also useful for people with clotting disorders.

“On the other hand, the same approach could help design clots that break down more easily as necessary, helping to prevent dangerous conditions like stroke or deep vein thrombosis,” he added. “Mechanical nudging allows us to make the material up to four times stronger or weaker, depending on what we need it to do.”

Why previous methods fell short

Earlier approaches to shaping living tissues relied on physical forces like magnets or ultrasound waves. While promising, these methods often fail to replicate the complexity of real tissues, which contain billions of cells and have thick, three-dimensional structures. In addition, they are often limited to specific materials, can damage healthy tissues and sometimes trigger immune responses.

The researchers’ study is the first to show that mechanical agitation, a very simple and widely accessible tool, can control the inner structure and performance of living materials in a “safe, scalable and highly tunable way.”

From the lab bench to living systems

To validate their findings, the team ran a series of tests to measure how vibration affected various cell-laden materials such as blood-based gels, plasma and seaweed-derived alginate. Using imaging and mechanical analysis, they assessed how broadly the method could be applied. Next, they tested the technique in animals.

The results showed that the technique works when applied inside the body, without harming surrounding healthy tissues.

Toward advanced medical technology

Bahmani said he believes the simple method could one day be integrated into advanced medical devices or wound-healing techniques.

“What makes this especially exciting is that our method is non-invasive, low-cost and easy to implement,” he said. “It does not rely on expensive machines or complex chemicals, meaning it could one day be built into portable medical devices, like a hand-held tool to stop bleeding, or a smart bandage that speeds up healing.”

He noted that the method requires further testing, such as in irregular wounds or in combination with certain medications, before it can be used in real-life medical settings.

“Moving toward clinical use will require miniaturizing the devices, optimizing settings for different medical scenarios and completing regulatory testing to ensure safety and effectiveness in humans,” he said.

About this study

“Engineering Highly Cellularized Living Materials via Mechanical Agitation” by Aram Bahmani, Jianyu Li et al was published in Advanced Functional Materials.

The research was funded by the Canadian Institutes of Health Research, the NSERC/FRQNT NOVA Program, the Fonds de Recherche du Québec-Nature et Technologies Doctoral Scholarship, the Canada Research Chairs Program, the Centre de Recherche sur les Systèmes Polymères et Composites à Haute Performance and the McGill Faculty of Engineering.

Likun Zhang, senior scientist at the National Center for Physical Acoustics and associate professor in the Department of Physics and Astronomy, led a research team studying how liquid waves move through barriers in low-gravity environments. Their results were published in Physical Review Letters.  

“In low-gravity cases like the space station, surface tension dominates everything,” said Zhengwu Wang, a fourth-year Ole Miss doctoral student in physics and co-author of the study. “The curvature of the water – the meniscus – is going to appear around structures, and we wanted to know how that meniscus would affect how waves move across barriers.” 

When water meets a partially submerged barrier – think of a leaf on a pond – the surface tension of the liquid causes the liquid to curve upward where it meets the barrier; in this case, the leaf. Zhang and Wang’s research shows that this curve, called the meniscus, can be manipulated to reduce or increase the amount of energy that passes through that barrier.  

 

If the meniscus’ curve is slight, more energy passes through. But as the meniscus curves more steeply, it reduces the energy conveyed by the fluid.  

“Our common sense tells us a barrier should block waves, but here we found certain meniscus shapes can make waves pass through more easily,” Zhang said. “Only a tiny, 1.5-millimeter change in the meniscus shape caused the transmission to drop from about 60% to just a few percent. Tiny meniscus, huge impact.” 

Space travelers use liquids for all manner of applications: from fuel and water-recycling systems to life support and cooling systems. Being able to better control the fluid in these systems can make them more efficient and lighter – a key for space travel. 

“These are really tiny effects in daily life, but they can have a huge impact in microgravity environments,” Wang said.  

To conduct the experiment, the researchers simulated low gravity by generating small, frequent surface waves. Then, they placed a partial barrier in the path of those waves and used acoustics to measure the meniscus’ movement.  

By changing the barrier’s height and using a surface coating to make it water-attracting or water-repelling, the researchers controlled the meniscus – and how much energy passed through the barrier.  

“As physicists, we are looking at very fundamental problems: the like problem of wave dynamics and barriers,“ Zhang said. “But being able to control fluid behavior in low gravity is crucial – whether you‘re talking about water recycling systems or fuel tanks – because you can‘t rely on gravity to separate liquids and gases.“ 

The applications could prove useful in earthbound manufacturing and biomedical engineering, too, where microfluidic devices move fluids through channels just millimeters wide, Zhang said. These devices range from printers to DNA chips to lab-on-a-chip technology.  

“This is the first experiment studying this behavior in fluid, but it opens the door to new phenomena and new physics,” he said. “This work is valuable because it shows a new way to control fluid for the first time.”  

This material is based on work supported by the National Science Foundation grant no. 2306106. 

Researchers in McGill’s Department of Mechanical Engineering have discovered a safe and low-cost method of engineering living materials such as tissues, organs and blood clots. By simply vibrating these materials as they form, scientists can dramatically influence how strong or, weak they become.

The findings, published in the journal Advanced Functional Materials, could have a range of innovative applications, including in organ transplants, wound healing and regenerative medicine.

Good vibrations

The researchers used a speaker to apply controlled vibration, gently agitating the living materials during formation. By doing so, they found they could influence how cells organized and how strong or weak the final material became.

The technique works across a range of soft cellular materials, including blood clots made from real blood and other human tissues.

Aram Bahmani, study co-author and Yale postdoctoral fellow, conducted the research at McGill as a PhD student with Associate Professor Jianyu Li’s Biomaterials Engineering lab. Bahmani explained that strong, fast-forming blood clots are vital for use in emergencies like traumatic injuries. They’re also useful for people with clotting disorders.

“On the other hand, the same approach could help design clots that break down more easily as necessary, helping to prevent dangerous conditions like stroke or deep vein thrombosis,” he added. “Mechanical nudging allows us to make the material up to four times stronger or weaker, depending on what we need it to do.”

Why previous methods fell short

Earlier approaches to shaping living tissues relied on physical forces like magnets or ultrasound waves. While promising, these methods often fail to replicate the complexity of real tissues, which contain billions of cells and have thick, three-dimensional structures. In addition, they are often limited to specific materials, can damage healthy tissues and sometimes trigger immune responses.

The researchers’ study is the first to show that mechanical agitation, a very simple and widely accessible tool, can control the inner structure and performance of living materials in a “safe, scalable and highly tunable way.”

From the lab bench to living systems

To validate their findings, the team ran a series of tests to measure how vibration affected various cell-laden materials such as blood-based gels, plasma and seaweed-derived alginate. Using imaging and mechanical analysis, they assessed how broadly the method could be applied. Next, they tested the technique in animals.

The results showed that the technique works when applied inside the body, without harming surrounding healthy tissues.

Toward advanced medical technology

Bahmani said he believes the simple method could one day be integrated into advanced medical devices or wound-healing techniques.

“What makes this especially exciting is that our method is non-invasive, low-cost and easy to implement,” he said. “It does not rely on expensive machines or complex chemicals, meaning it could one day be built into portable medical devices, like a hand-held tool to stop bleeding, or a smart bandage that speeds up healing.” 

He noted that the method requires further testing, such as in irregular wounds or in combination with certain medications, before it can be used in real-life medical settings.

“Moving toward clinical use will require miniaturizing the devices, optimizing settings for different medical scenarios and completing regulatory testing to ensure safety and effectiveness in humans,” he said.

 

About this study

“Engineering Highly Cellularized Living Materials via Mechanical Agitation” by Aram Bahmani, Jianyu Li et al was published in Advanced Functional Materials.

The research was funded by the Canadian Institutes of Health Research, the NSERC/FRQNT NOVA Program, the Fonds de Recherche du Québec–Nature et Technologies Doctoral Scholarship, the Canada Research Chairs Program, the Centre de Recherche sur les Systèmes Polymères et Composites à Haute Performance and the McGill Faculty of Engineering.