Solid State Technology and Devices Seminar: Plastic electrochemical devices: from wearable sweat sensors to artificial synapses
Seminar | October 6 | 1-2 p.m. | Cory Hall, 521 Cory (Hogan Room)
Professor Alberto Salleo, Professor, Stanford University
Organic semiconductors have been traditionally developed for making low-cost and flexible transistors, solar cells and light-emitting diodes. In the last few years, emerging applications in health case and bioelectronics have been proposed. A particularly interesting class of materials in this application area takes advantage of mixed ionic and electronic conduction in certain semiconducting polymers. Indeed, the ability to transduce ionic fluxes into electrical currents is useful when interacting with living matter or bodily fluids. My presentation will focus on two families of devices made with such materials: electrochemical transistors and artificial synapses.
1- Wearable sensors using electrochemical transistors: The continuous monitoring of human health can greatly benefit from devices that can be worn comfortably or seamlessly integrated in household objects, constituting health-centered domotics. I will describe electrochemical transistors that detect ionic species either directly present in body fluids or resulting from a selective enzymatic reaction (e.g. ammonia from creatinine) at physiological levels. Additionally, I will show that non-charged molecules can be detected by making use of custom-processed polymer membranes that act as synthetic enzymes. Using these membranes in conjunction with electrochemical transistors we demonstrate that we are able to measure physiological levels of cortisol in real human sweat.
2- Polymer-based artificial synapses: The brain can perform massively parallel information processing while consuming only ~1- 100 fJ per synaptic event. I will describe a novel electrochemical neuromorphic device that switches at record-low energy