Prof. Yael Hanein has a dream: to restore sight to the blind. Of course, this is a long-term vision, but her more immediate goal is also ambitious: to communicate with neural networks in the brain via nanotechnological devices.
Such communication poses a tremendous challenge because, among other things, it requires creating a bridge between two different worlds: that of physics and engineering on the one hand, and that of biology on the other, explains Hanein, Director of Tel Aviv University’s Center for Nanoscience and Nanotechnology. Communication in these two worlds is conducted in different languages: In “hard” engineering systems, electricity is transmitted by the flow of electrons, whereas in such “soft” biological systems as nerves, electrical signals are relayed by a flow of charged ions in a solution.
This means that a device implanted into the human body to replace damaged nerve tissue must not only be materially compatible with body tissues but also able to communicate with these tissues. How can the difficulties in “translation” be overcome?
Hanein proposes tackling the problem with implants made of microscopic carbon nanotubes. Thanks to their unique atomic structure, these nanomaterials combine elasticity with extraordinary strength. But perhaps most important is that the thin-walled tubes create an unusually large surface relative to their mass, which facilitates the transmission of signals from electrodes in these devices to nerves. In addition, nerve tissue clings firmly to their surfaces and grows well upon them. Devices fashioned in this way can greatly contribute to brain research, helping to clarify the biological basis of neurological diseases and the impact of drugs on the brain.
Hanein envisions one day implanting such devices into human eyes to replace retinas damaged, for example, by age-related macular degeneration, a common cause of vision loss in the elderly. The implant would transmit signals from the outside world to the brain in the neurons’ language.
A number of retinal implants have already been developed, including one that has been approved for use in humans in the United States and Europe. In Israel, such implants are being developed by Nano Retina, in which Hanein serves as a vice president. But according to Hanein, the entire field is still in its infancy: “It is still at about the same stage as the aeronautics industry when the first planes lifted off the ground and managed to fly for about a hundred meters.”
In her lab at Tel Aviv University’s School of Electrical Engineering, Hanein makes use of the scientific methods she learned during her master’s and doctoral studies in experimental physics at the Weizmann Institute’s Joseph H. and Belle R. Braun Center for Submicron Research
: studying the flow of electrical charges, characterizing semiconductors, coating materials with nanolayers. Hanein’s doctoral research, under the guidance of Prof. Dan Shahar
of Weizmann’s Condensed Matter Physics Department, focused on two-dimensional quantum Hall systems. She recalls: “From the moment I arrived at Weizmann as a student, I received all the resources – the scholarship, the access to labs. The message was: Just study and succeed.” Hanein now seeks to convey the same message to her own students: “My stint as a Weizmann student is still my example. The Institute gives students a home – the optimal environment for developing as a researcher.”
During her postdoctoral studies at the University of Washington in Seattle, she became interested in interdisciplinary research combining physics with chemistry, electrical engineering, materials science and biology, which led her to her current topic. Since returning to Israel and joining the faculty of Tel Aviv University in 2003, Hanein has received recognition for her work, in Israel and abroad. She was among the founders of the Global Young Academy and has lately been appointed a member of the Israeli Young Academy of the Israel Academy of Sciences and Humanities.
Hanein engages in her research with such intensity that during her leisure, she needs equally intensive activity to take her mind off work. Her favorite vacations have involved long hikes – in Ireland, Scotland and Japan – walking some 20 kilometers a day. In her other hobby, reading, she particularly enjoys history books that deal with human behavior at the level of groups or societies.
As a woman working in a traditionally male field, Hanein naturally gives much thought to the place of women in science. She is the only woman among 27 faculty members in the Department of Physical Electronics at Tel Aviv University; of the 66 scientists in the Center she directs, only eight are women. Hanein believes that in order to correct this situation, it’s important to determine how it comes about: “Electrical engineering can be a good profession for women, but its image needs to be changed. Just like the ‘gentler’ biomedical fields, it has applications that can help treat diseases and improve people’s lives.”