Recent developments in material science and electrical engineering combine the optical control with the use of soft, flexible optoelectronic implants that deliver light directly to regions of interest using ultraminiaturized μLEDs, which powered and controlled wirelessly. Such devices enable a range of experiments with freely behaving animals, in isolation or in social groups, and in simple or elaborate environments. The prospects of wireless optogenetics have already generated significant interest from companies such as NeuroLux and Cambridge Neurotech, which are developing wireless implants based on the Radio Frequency (RF) based energy harvesting. However, these systems require external tracking mechanism to track the motion of a mouse or rat for effective power transmission. Another EU project STARDUST, developing the ultrasound based wireless implantable and independent micro-scale device for optogenetics to treat the Parkinson’s disease. Ultrasound based wireless systems enables low signal attenuation in biological tissue, minimized geometry, and can be used safely with human. Nonetheless, complicated circuitry and complexity in addressing the ultrasound frequency remain the main bottlenecks. In addition, ultrasound based wireless system has low data rate, has a signal is greatly attenuated by the skull and needs an intermediate transceiver based on electromagnetic coupling beneath the skull. Photovoltaic based energy harvesting from light is another option that has been explored to wirelessly power the neural implants for optogenetics. Due to the lossy nature of biological tissues, photovoltaic based system suffers from low efficiency14 as well as light sources nature, proximity, and direction limits the solar cells wireless powering ability for implantable neural devices. Due to the special properties (e.g. negative refractive index), metamaterials have been used to improve the WPT efficiency, operating range, and larger misalignment tolerance for electronic devices.
A metamaterial is defined as an artificial composite that gains its electromagnetic properties from its engineered structure rather than the materials it is composed of. This is the first time, this fellowship uses a novel self-tracked high dielectric-metamaterial based WPT systems for optogenetics. This wireless powering system will be integrated with a unique multichannel scalable neural implant. Apart from fabrication of neural implants through biocompatible polymer, this probe will achieve the implant-tissue biointegration by using the novel PEA encapsulation for chronic in vivo functionalities and to promote the MRI compatibility. The probe is ready for in vivo test, which will be performed in December or next year as we are waiting for the appropriate rodent model to arrive in December.
The impact of this research is obvious as due to the unique application of metamaterials in wireless optogenetics and healthcare helped me to secure my position as a Lecturer at the University of Exeter, which I started immediately after this fellowship. The University of Exeter is renowned for Metamaterial research and being aligned with the current quest to understand the brain (e.g. EU human brain project, US presidential BRAIN initiative, IEEE brain), the WiseCure Fellowship paved me to establish myself as a key player and a leader in the field of implantable bioelectronics, nanofabrication and neural engineering to pursuit of new and innovative ideas, and to provide control over the future direction in neural engineering.
At the University of Glasgow, this fellowship helped me to be a part of two more big grants CROSSBRAIN (GA n.101070908) and BRAINSTORM (GA n.101099355) as a Co-I, which indicates investment and creation of new technology, bringing with it the opportunity for new jobs and wealth creation. These synergies will promote the long-term impact of WiseCure on EU economy, healthcare and society.
