Bioengineering is the intersection of biology, engineering and physics. As is often the case in science, some of the most interesting discoveries occur in ways that don’t fit the neat categories humans try to impose upon science.

As a medical doctor with a doctorate in engineering, Sangeeta Bhatia is well poised to explore the junctures of biology and engineering.

An assistant professor of bioengineering at UCSD’s Jacobs School of Engineering, Bhatia is applying semiconductor technology to biology. Her lab is building tiny machines called biological micro-electro-mechanical systems, or BioMEMS, to study and possibly treat the body from the inside. Another focus of Bhatia’s work is liver function.

In keeping with her education, Bhatia’s collaborations make her a nexus between biological and inorganic sciences

One of her collaborations is with fellow UCSD researcher Michael Sailor, who is developing MEMS for use as miniature observation devices — mobile, possibly flying specks of semiconductors using silicon as a propellant as well as the brains of its circuitry.

Bhatia is working with Sailor to develop a dime-sized bioreactor from silicon that can support the growth of liver cells. The bioreactor’s porous surface would house the cells, and the device could be fine-tuned to regulate the flow of nutrients and keep out bacteria and viruses.

The goal of this research is to allow liver cells to function as normally as possible, even when grown outside the liver. This could become the basis for an artificial liver.

Another goal of the collaboration with Sailor is to develop biological sensors that could detect chemical or biological agents, an area of intense interest since the Sept. 11 attacks.

Bhatia taps into biology through another collaboration with Erkki Ruoslahti, a distinguished professor at the Burnham Institute. The collaboration’s goal is to use semiconductor crystals called quantum dots to detect cancer. Ruoslahti provides small protein molecules called homing peptides that guide the quantum dots to their target.

As a woman in science, Bhatia is a rarity, and she has a personal interest in encouraging girls and young women to take up scientific careers.

Engineering, of course, has long been a traditional male bastion. Bhatia, who got her engineering degree from Brown University, was one of just 12 women in her class. She decided to do something about it. While in graduate studies at MIT, Bhatia co-founded a program called Keys to Empowering Youth, which provides science and technology workshops for 11- to 13-year-old girls.

Bhatia arrived at UCSD in 1998 after training at Harvard and the Massachusetts Institute of Technology. At UCSD, she set up a full-day science program aimed at getting young girls interested in a science career.

Another Bhatia initiative was to hold a spring banquet for female engineering students. The banquet, held by the Society of Women Engineers, features speeches by female engineers who describe how they overcame obstacles to success in the engineering field. This year Sally Ride, the first female astronaut, spoke at the banquet.

“I saw so many women dropping out of engineering, while other fields — medicine, law, business — have growing numbers of female students. There’s something wrong,” Bhatia says.

The 34-year-old grew up west of Boston and is married to Jagesh Shah, a biophysicist who works on cancer research at the Ludwig Institute.

She also enjoys her life outside the lab. “In my free time I like to travel,” she says. “I belong to a book club, and since moving to California four years ago I have tried surfing, paragliding and hot yoga.”

— Bradley J. Fikes