Chemical circuits that govern our neurons
A year as an exchange student at Stanford caused Klas Tybrandt change track. He has just defended his Ph.D. in organic bioelectronics, where he demonstrated how chemical chips could control signalling in the body’s cells.
Tybrandt’s Ph.D. thesis is complete and several sections have already aroused great interest, even outside the world of science. In the spring of 2010, PNAS published the section of the thesis Tybrandt himself was most pleased with and which might be said to be a breakthrough for a new field within bioelectronics. PNAS is the Proceedings of the National Academy of Sciences.
He succeeded in creating a fundamental component: an ion transistor capable of controlling chemical substances in the same way an electronic transistor controls currents.
The cells in our bodies signal with the aid of various signalling substances, such as sodium, potassium or calcium, but also with large molecules such as acetylcholine, a substance that transmits nerve signals to our muscles as one of its functions. In 2010, researchers at Karolinska Institutet were able to show that it was possible to send acetylcholine to neurons with the aid of the component that Tybrandt, together with professor Magnus Berggren, developed in the ‘cleanroom’ at the Department of Science and Technology, Campus Norrköping.
The next step was to make entire chemical circuits based on ion transistors. In the spring of 2012, it was time for the next breakthrough when Nature Communications published the last chapter in his thesis, which received attention far beyond the world of science. Tybrandt succeeded in building a chemical chip, a NAND gate, which forms the basis of all digital technology.
That breakthrough also lays the foundations for a whole new technology of circuits, based on ions and molecules. When the chemical chips are attached to our neurons, signals can be transmitted which could, for example, reduce pain or stop the progression of disease. The technology can also be attached to existing electrode systems in order to improve and develop functionality. Such systems are currently used in the treatment of serious cases of Parkinson's and chronic pain.
“The chemical circuits can both transport the signal substance and regulate how much is transported,” says Tybrandt.
His interest in organic bioelectronics surfaced while studying at Stanford University as an exchange student.
“I was on the engineering physics and electrotechnology programme, and I sneaked my way into polymer physics and polymer semiconductors during the year.”
His Ph.D. thesis, under professor Olle Inganäs, was on organic solar cells and when the Ph.D. was all but finished, he was offered a tempting research fellowship with Magnus Berggren in the organic electronics group at Norrköping.
“This is a rather new field, but it is in the process of expanding rapidly on an international scale. A number of the research groups who have devoted themselves to displays and solar cells have now begun to look at the biological applications,” he says.
He will remain with Berggren's research group a while longer. A post doc abroad is an attractive prospect, but so is a job in the industry. While he thinks about these choices, he has undertaken a challenge, together with Berggren and the others in the research group, to develop increasingly complex circuits that can constitute a reliable bridge between electronics and the biological systems by translating electronic signals to those of the human body.
Thesis: Ionic Circuits for Transduction of Electronic Signals into Biological Stimuli, Klas Tybrandt, Department of Science and Technology, Division of Physics and Electronics, Linköping University, Campus Norrköping. 2012.
Illustration: Ingemar Franzén
Related Internal Links
Related External Links
- Ion bipolar junction transistors in PNAS
- Logic gates based on ion transistors in Nature Communications
Last updated: Tue Jun 07 07:54:13 CEST 2016