报告摘要：Micro Electro Mechanical Systems (MEMS) are versatile technologies which have evolved over recent decades due to the increasing capabilities to miniaturize structures and devices. However, the majority of micro devices is still powered by external, macro-scale power sources. Interconnection problems, unwanted electronic interactions (noise), and difficulties in controlling the power delivered are some of the problems which can be associated if macro-scale power sources are coupled with micro-scale devices. One possible approach to ease such difficulties is through the utilization of integrated power sources. In this talk, we report on the fabrication and characterization of two different devices which can be easily integrated on MEMS (and microfluidic) devices which are made from glass-like (silicon dioxide) substrates:

 

i) A micro battery where we employ different microfabrication techniques, such as Physical Vapour Deposition, to fabricate thin-films of nickel hydroxide and metal hydride which serve as battery electrodes. These electrodes are arranged in a co-planar design and ionically connected with an alkaline gel electrolyte.

 

ii) A supercapacitor which is made by printing of graphene oxide (GO) inks on glass using a micro-dispensing technique. The printed GO electrodes are subsequently treated to obtain reduced graphene oxide (rGO). The micro dispensing technique utilizes a liquid jet which, in contrast to ink jet printing, should not break up and form droplets. However, we operate at very high Froude numbers and parameters to obtain stable print regimes are not known. We introduce a combined empirical and analytical approach to infer the critical jet length to nozzle diameter ratio and the jet shape function.  

 

报告人简介：Dr. Dominik P.J. Barz is an Associate Professor at the Department of Chemical Engineering at Queen’s University. He received a Diplom-Ingenieur FH (B.Eng.) in Mechanical Engineering at Aachen University, Germany in 1996. He then held several positions in industry and public sector companies in Germany such as a lab engineer at the Mercedes Benz Fuel Cells Lab at FHTG Mannheim and a (Senior) Research Engineer working on Lab-on-a-Chip technologies at Forschungszentrum Karlsruhe GmbH. During these full time employments, he pursued further (part-time) studies and graduated with a Diplom-Ingenieur (B.Sc.+M.Sc.) with distinction in Chemical Engineering from TU Dresden and as a Doktor-Ingenieur (Doctor of Engineering Science) with distinction in Mechanical Engineering from University of Karlsruhe (now Karlsruhe Institute of Technology KIT). He then joined Cornell University, US working with Prof. Paul Steen on interface and transport phenomena in porous media. He joined Queen’s University as a faculty in 2010 and took up the post of an Associate Director of the Queen’s-RMC Fuel Cell Research Centre.

 

He is the recipient of several awards including a Helmholtz Association Microsystems Scholarship, the ASME ICNMM outstanding leadership award and the Ontario Early Researcher Award. During 2016-2017, he was awarded an Alexander-von-Humboldt Research Fellowship that he spent at the Centre of Smart Interfaces, TU Darmstadt, Germany.

 

His academic and industrial experience has been in areas encompassing both Mechanical and Chemical Engineering subjects and, hence, his current research includes transport & interface phenomena, microfluidics, as well as the miniaturization of electrochemical devices.