Nanotechnology Research in Germany!
Throughout my time at the lab I focused on developing testing protocols for a multiplexed cortisol sensor. The sensor used a series of Field Effect Transistors and detected cortisol concentrations through running microfluidics tests over the multiplexed sensors. The overall goal was to correlate the output curves with the concentration of cortisol that is in the microfluidic solution. The project group I worked with focused on flexible Field Effect Transistors which will have applications in Biochemical Screenings, Health Care Monitoring, and be able to be used as a “lab-on-a-chip.” Applications in medicine and bioprocess engineering will benefit from this research and development.
Project Debrief:
My time at the lab was a very insightful and educational experience. I learned from a very diverse and multi-national team. As I developed a testing method to quantify the data gained from the multiplexed sensor, I learned wire bonding techniques, chemical wet lab procedures, probing techniques involving a probe station to check for damaged and broken transistors on the multiplexor, as well as diagnosing circuit board issues. On the days where the lab ran into equipment issues, I shadowed other members of the lab and witnessed the creation of a transistor through spin-coating a layer of photoresist onto a silicon wafer, placing a mask, performing UV lithography, plasma etching, and metal deposition as well as electron beam lithography procedures.
At the end of my time at the lab, using the Digilent Oscilloscope 2, I developed a protocol that tested the multiplexed cortisol sensor. I wirebonded the multiplexed FET chip to a PCB that had leads attached to the input of the oscilloscope. I then made solutions of varying molarities to be run using a microfluidic pump and a PDMS channel attached to the chip. A circuit was then constructed to facilitate and interface the gate, source, and drain terminals of the transistor to the oscilloscope. The oscilloscope was then set to sweep various voltages to obtain an output curve. The resistors and the swept voltages were changed to optimize the output curve until it began to resemble a commercial transistor value.
