It looks like a simple cosmetic procedure or tattoo, but without needles and no pain. Instead, a microscopic jet of medicine shoots through the skin, leaving behind a treatment and a mark that shows whether it works. This needle-free injection is a glimpse of a future where bubbles powering microjets replace needles, pills, and even some surgical procedures. For Professor David Fernandez Rivas, this is not science fiction, but the direction his research on microbubbles and microjets is taking us. On 16 October 2025, he will deliver his inaugural lecture at the University of Twente.
David Fernandez Rivas’ research focuses on the mass transport and fluid dynamics phenomena at extremely small scales: microfluidics. Within these tiny channels, droplets and bubbles behave differently than they do in our everyday world. That difference opens up entirely new ways to manipulate liquids and particles with extreme precision.
“Each tiny jet we create with small bubbles is like a messenger,” says David Fernandez Rivas, professor of microfluidics at the University of Twente. “It carries kinetic energy or medicine precisely where we want it, without harming the tissue around it.” One of the best-known applications is the needle-free injection: using a jet (long droplet) of fluid to deliver medicine painlessly into the skin. But the same principle can also be applied to diagnostics, bioengineering research, and energy-efficient manufacturing.
A scientist, artist and entrepreneur
As both a researcher and entrepreneur, Fernández Rivas bridges the gap between lab and society. His spin-off companies translate microfluidic discoveries into real-world devices, from medical injectors at FlowBeams, to miniature reactors that save energy at BuBclean.
Outside the lab, he collaborates with artists and tattooists to explore how technology can transform the way we experience our bodies. A tattoo, for instance, can now carry both artistic and therapeutic meaning. “Science and art have a lot in common,” says Fernandez Rivas. “Both are about making the invisible visible and both can change how we see ourselves.”
Small is beautiful
If it’s up to Fernandez Rivas, the next decades of medicine will be defined by precise, and personalized technologies. Instead of large-scale machines and painful procedures, we may soon rely on wearable or even invisible systems that continuously monitor and maintain our health. “The smaller we go, the closer we get to the human experience,” he says. “When technology disappears into our skin, that’s when it truly becomes part of us.”
Whether it’s drug delivery, diagnostics, or wearable health monitoring, Fernandez Rivas’s message is clear: micro is not the opposite of impactful. Tiny bubbles and jets might soon help address some of medicine’s biggest challenges. Proving once again that sometimes, the smallest ideas make the biggest difference.
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Prof Dr David Fernandez Rivas is a Professor of Chemical and Biomedical Microfluidic Systems in the research group Mesoscale Chemical Systems (MCS; Faculty of S&T / MESA+). He is most well-known for his work on needle-free injections which he successfully valorises into the UT spin-off company called FlowBeams. On October 16, he shares his vision during his inaugural lecture “Tiny Jets and Bubbles: Taming global challenges with entrepreneurial engineering” at the University of Twente.
