Page 96 - Undergraduate Research Opportunities Program Proceedings 2017-18

School of Engineering
Department of Mechanical & Aerospace Engineering

Department of Mechanical & Aerospace Engineering

Resuspension of Aerosols from Building Surfaces

Supervisor: CHAO Yu Hang Christopher / MAE
Student: JEYAKUMAR Aadhithya Vignesh / MAE Course: UROP1100, Fall

The UROP study is led by Professor CHAO Yu Hang Christopher. The resuspension phenomenon of an aerosol from
different building surfaces was studied. It is of relevance because the resuspension phenomenon is of concern in various
processes such as disease transmission, contamination during manufacturing of microelectronics, surface
decontamination and filtration. This project aims to study the effects of different surface roughness of the plastic
PMMA substrate on the resuspension behaviors of the liquid droplets. The liquid droplets used were glycerol. The
substrate used was poly(methyl methacrylate) (PMMA). Different surface roughness was achieved by sanding process.
The centrifuge method was employed.

Proton Sensing Electrodes for Electrochemical DNA Sequencing

Supervisor: CHEN Qing / MAE
Student: WANG Zhien / CHEM Course: UROP1100, Fall

Among the newly-developed DNA sequencing technology, electrochemical DNA sequencing stands out for its high
efficiency and low cost. Using direct electrical detection of pH changes during DNA synthesis, the sensitivity and stability
of pH sensing electrode is closely related to the accuracy. In our experiments, the transparent conducting oxide, Indium
tin oxide (ITO)2 is used as the pH-sensing electrode. Its high transmittance in visible light region and high electrical
conductivity promise the potential implementation in DNA sequencing. We investigated the stability and proton
sensitivity of an ITO electrode is investigated. The result shows an approximate linear relationship between pH and
voltage in basic solutions but low stability of ITO in acidic environment. We will discuss a possible explanation of
instability and propose methods to improve it at the end of this report.

Design of Optical Encryption Device by Objective Structure and Twisted Light

Supervisor: CHEN Sherry / MAE Co-Supervisor: DU Shengwang / PHYS
Student: LI Bohan / PHYS-IRE Course: UROP1100, Summer

Twisted light is defined to be a form of EM field that exhibit a diffraction free property, which is also known as Bessel
beam. Twisted light as a rigorous expression of Bessel beam consists of two Bessel functions of different order and with
left-circular and right-circular polarization; it could be considered as a sum of those two independent Bessel beams. We
divide a spatial light modulator into two regions and use each of them to generate an independent Bessel beam. Two
beams are combined together through optical alignment and switch to left and right circular polarization using a quarter
wave plate.

Design of Energy Conversion Device from Heat to Electricity

Supervisor: CHEN Sherry / MAE
Student: SUEN Ho Yuen Henry / MAE Course: UROP1100, Summer

86