Bridging Physics and Biology
© H. Raguet/CNRS Photothèque
The meeting takes place at the Paris Descartes University, in the heart of Paris's famous Saint-Germain-des-Prés neighborhood. Valentina Emiliani, a renowned physicist with a lilting accent that betrays her Italian origins, takes me up three floors to the laboratory where she works, specialized in neurophysiology and new microscopies (LNNM).1
By way of introduction to her complex field of study, Emiliani sums up her work as lying at the interface between physics and biology. It has now been nearly four years since this specialist in optical properties of quantum semiconductors set up one of the lab's four teams. The team's goal is to develop novel microscopy techniques for neurophysiology.
Now 42, this native Italian is enjoying her life as a researcher, after a circuitous career that took her from Italy to France. When she started out, Emiliani, who grew up in Rome, was as keen on architecture as she was on physics. She chose physics “because of my family's attachment to research.” She studied for her PhD at the University of Rome while working with a non-linear optics lab2
located in Florence.
Then, in 1996, she was offered a job in surface physics in Rome. “It was a bit too soon for me and, above all, a bit too far removed from my field of research,” she explains. Before accepting the job she decided to find out about surface physics by doing a postdoc at the Berlin Technical University. Emiliani was possibly more captivated by the German capital than by her new discipline. So she stayed in Berlin, but moved to a laboratory dedicated to the recently developed near-field optical microscopes, which have high spatial resolution.
In 2000, she returned to Florence, knowing full well what she wanted to do: apply this state-of-the-art technology to biology. It was then that France came knocking, mainly through her Italian researcher husband. “Things were complicated, because he was working in France,” Emiliani recalls. In 2002, fed up with endless travels back and forth, she opted for a postdoc at the Institut Jacques Monod in Paris. Both the change in her status and the language handicap weighed heavily on her, and she missed her independence. But this didn't stop her from continuing to investigate the links between physics and biology, by studying the reactions of cells to mechanical stimulation of their environment. “To do this, we used optical, so-called holographic, tweezers,”3
she explains. “Based on special types of laser beams, they can be used to stimulate cells in their three dimensions. It was during this project that I realized that holographic manipulation of light opened up other applications in biology.” In 2004, she obtained a position at CNRS. To carry out her project, however, she wanted to have her own team. A stroke of luck led her to cross paths with LNNM Director Serge Charpak, who wished to strengthen the physics in the laboratory, and they struck a deal. She successfully applied to the 2005 European Young Investigator Award (EURYI Award), and was able to move into her new premises, purchase state-of-the-art optical equipment, and build an invaluable team. “Here, the permanent contact with biologists in the lab combined with their awareness of the role of physics allow us to share a common language,” she says. This is a perfect setting to extend the use of holography to other applications, such as exploring, both in time and space, the mechanisms of communication between neurons.
With a renowned team, and having fully embraced the offerings of France's capital city, Emiliani has postponed her return to Italy, maybe indefinitely.
1. Laboratoire neurophysiologie et nouvelles microscopies (CNRS / Université Paris-V).
2. Non-linear optics makes use of the intense electric fields produced by lasers to alter the optical properties of the medium they pass through.
3. The use of highly focused laser beams as optical tweezers to manipulate cells or small objects.