Electrical neural recordings are based on the measurement of voltage differences by an electrode located in the proximity of neurons. Currently at Neuro-Electronics Research Flanders (NERF), in collaboration with imec, we are working on developing large-scale, high-density, flexible neural probes that can offer high spatial resolution and spatial sampling coverage of the brain tissue. To overcome some limitations of passive neural probes, such as limited electrode count and connector size, we have decided to employ active electronic circuits that allow the multiplexation and amplification of the neural signals.
The flexible neural probes we are developing are based on thin-film transistors (TFTs) that utilize metal oxide semiconductors as the channel layer. These devices have attractive characteristics, such as high uniformity, high electron mobility (10 cm2/V‧s), and their fabrication at low temperatures on plastic substrates. The fabrication flow of our TFTs was initially developed at imec to be used for flat-panel displays. Since the operational conditions in-vivo application are harsher, changes in the process flow, material stacks and interface should be implemented to customize to the requirements for neural probes.
The objective of this thesis is to work on the microfabrication of the designed neural probes, and to explore variations of the current process flow that can achieve devices with excellent characteristics for the measurement of biosignals. Significant effort will be placed on improving stability of the device in saline environments to avoid delamination of the different layers, which limits the life time of our devices. Additionally, the incorporation of the TFT's in stretchable polymeric substrates will be explore. The work will also include the electrical characterization of the fabricated devices.
Previous cleanroom and fabrication experience is desired but not required.
Type of project: Internship
Duration: 6-12 months
Required degree: Master of Engineering Technology, Master of Science, Master of Engineering Science
Required background: Electromechanical engineering, Electrotechnics/Electrical Engineering, Materials Engineering, Nanoscience & Nanotechnology, Physics
Only for self-supporting students.