PhD Project by Mohammad Ramezannezhad

Project Title: Advanced carbon micro- and nanofabrication for electrochemical energy systems
Group: Biomaterial Microsystems
Supervisor: Stephan Sylvest Keller

Project Description
According to the significant development of micro- and nanofabrication techniques and their superior properties, they have drawn lots of attention during these years. On the other hand, energy storage is an important matter due to the development of various technologies such as sensor network for the internet of the things. Among different types of energy storage devices, micro super capacitors have been identified as ideal candidates due to their excellent power densities and cycling lifetime.

Although micro super capacitors showed suitable performance, their planar types still suffer from vast unused area, low specific capacitance, and power capabilities. Therefore, fabricating a 3D electrode structure provides additional surfaces of sidewalls, faster mass transport kinetics and shorter ion electron diffusion distances, and higher areal capacitance and energy densities. Silicon deep reactive ion-etching (DRIE) is a standard and well-known microfabrication process, which is capable to produce different patterns with high aspect ratio and surface area. Besides, combination of 3D silicon structures, SU-8 photolithography, and carbon pyrolysis processes results in fabrication of promising device for energy storage application.

Perspective
The hypothesis of this project is to implement and optimize novel strategies for cleanroom-based micro- and nanofabrication of 3D carbon microelectrodes (3DCME). It will be performed by optimization of photolithography processes and exerting silicon etching processes to increase the efficiency of the device by different approaches such as minimizing the distance between two terminals of interdigitated electrodes, increasing the surface area, increasing the mechanical stability of the structure, and fabrication of more 3D complex architectures.