Numerous technologies have been developed over the years for implantable devices that can be used for brain stimulation. The current solutions, however, are based on implanting electrodes that target a large area of the brain. The field of optogenetics, which was recently introduced, proposes to improve the accuracy of stimulation by genetically engineering neurons that are sensitive to light at a specific wavelength. While wireless optogenetic solutions have been developed, they are not practical enough to be embedded into the brain long-term. The focus of this presentation is to present the Wireless Optogenetics Nano Device (WiOptND), which is a micrometer scale device constructed from nano-scale components. The miniaturization of the device to the micrometer scale will enable it to be implanted into various parts of the brain, and to stimulate small population of neurons. The seminar will first cover the types of nano-scale components required to construct the WiOptND device, and how the properties of each components will provide new approaches for control signaling as well as wireless charging. The miniaturization of the WiOptND will also enable multiple devices to be placed in the brain, whereby a nanonetwork can be formed to target distributed stimulations. Variations of different charging protocols will also be presented to demonstrate how the coordinated charging process can enable the WiOptND nanonetworks to stimulate different neurons. A channel model that captures the peculiarities of light propagation in the neurons will also be presented, to analyze the light propagation behavior based on the photon transport through the nervous tissue. This includes analyzing the scattering light diffraction and diffusive reflection that results from the absorption of neural cell chromophores. Lastly, the seminar will touch on a number of applications as well as future directions for the wireless optogenetic nanonetworks.
Sasitharan Balasubramaniam (Sasi) received his Bachelors of Engineering (Electrical and Electronic) and PhD degrees from the University of Queensland, Australia, in 1998 and 2005, respectively, and Masters of Engineering Science (Computer and Communication Engineering) degree in 1999 from the Queensland University of Technology, Australia. After completion of his PhD, Sasi joined the Telecommunication Software & Systems Group (TSSG), Waterford Institute of Technology, Ireland where his research focused on bio-inspired communication networks. In 2009, he successfully received the Science Foundation Ireland Starter Investigator Research Grant, which allowed him to create a Bio-Inspired Research Unit. In 2013, Sasi joined the Department of Electronic and Communication Engineering, Tampere University of Technology, Finland, where in 2014 he received the Academy of Finland Research Fellow grant. As of 2017, Sasi is also the Acting Director of Research for the TSSG, and is the PI for the recently funded Science Foundation Ireland VistaMilk research centre. Sasi has published over 100 journal and conference papers, and actively participates in various conference committees. He was the TPC co-chair for ACM NanoCom 2014, and in 2015 he was the General co-chair. He is currently an editor for the IEEE Internet of Things journal, Elsevier Nano Communication Networks, as well as Elsevier Digital Communication Networks journals. His current research interests include molecular and nano communications as well as the Internet of Nano Things. Sasi is currently an IEEE Senior Member.