Even after two years of study, Van Vliet says she's not sure why bacteria adhere better to stiffer surfaces, but it's a question she hopes to unravel. What is clear is that knowledge of bacteria's mechanical responsiveness opens up a new approach to engineering antibacterial coatings.

"This is definitely an exciting result and a new factor people haven't considered," agrees Helen Blackwell, a chemist at the University of Wisconsin who studies bacterial communication. Other researchers have designed coatings that burst bacterial walls or that are simply so smooth or water-repelling that it's difficult for bacteria to settle on them. Van Vliet says that these approaches could be combined with her own. For example, the MIT group has already demonstrated that bacteria-killing silver nanoparticles can be embedded in the soft polymers.

Any advance in this area would be good news for patients. Frequently, the only way to remove an established biofilm is to mechanically scrape it off. "But you can't do that to medical implants," says Van Vliet.

There's another side to the MIT work: Van Vliet says that there are situations in which it would be beneficial to use stiff coatings in order to encourage bacterial growth. Most bacteria, including the majority of those living in our bodies, are hard to study because they can't be cultured in the lab using traditional methods. Blackwell agrees with Van Vliet that investigating materials that promote bacterial adhesion could be a "great way" to approach this problem.

According to Thomas, the MIT work could "revolutionize" the study of bacteria, and it shows that "we haven't been seeing a huge part of the picture."