Eric Y. Ma

Closed (1) Frugal science: high-performance microwave reflectometry using commercial wifi/cellular components

Applications for fall 2021 are now closed for this project.

Highly sensitive microwave (MW) reflectometry electronics, like those used in Microwave Impedance Microscopy for probing local electronic properties in solids (see e.g. https://science.sciencemag.org/content/350/6260/538), have been built with bulky, expensive, highly specialized components so far. This project aims to explore the possibility of using high-volume, cheaper, but still high-performance components made available by the wifi and cellular industry in recent years.


You will start by learning the basics of MW electronics, material-MW interaction, and the general design of MW reflectometry. You will then research into the specs of relevant off-the-shelf wifi/cellular components to generate a list of potentially viable components, the cost-performance trade-off, and a comparison with their more specialized counterparts. I think a narrow-bandwidth system at the common wifi/cellular frequency of ~1-2.4 GHz is probably a good starting point.

Depending on the result of this assessment, your time commitment, and whether you will continue working on this in Spring 2022, the outcome can vary from a feasibility report (possibly with negative conclusions) to an actual system, built, tested, and ready to be integrated with e.g. an optical or scanning microscopy setup. In the latter case, we can likely write a paper suitable for the Review of Scientific Instruments. That being said, regardless of the deliverables, you will have learned best practices of soldering and torque wrenching, have written Python codes to control a digital microwave attenuator through a microcontroller and to test it with a vector network analyzer, have done quite a bit of noise analysis, and have been part of an exciting journey of setting up a state-of-the-art optics/optoelectronics lab from scratch.


Qualifications: Required: motivation to spend the time and learn new skills, basic E&M knowledge, experience in gathering information on a specific topic and in reading spec sheets (https://en.wikipedia.org/wiki/Data_sheet). Good to have: experience with microwave electronics, Python, or solid-state physics

Weekly Hours: 9-11 hrs

Closed (2) Real-time Cloud-enabled lab environment monitoring with Internet of Things

Applications for fall 2021 are now closed for this project.

Modern optics labs require clean-room level air quality and extremely stable temperature & humidity control, all with minimal acoustic noise and air currents. Many projects that involve precision measurements further require minimal electromagnetic interference noise. However, the environment monitoring in most campus labs is limited to a single temperature sensor connected to a building network, generally not accessible by the lab users. In the age of cheap multi-parameter sensors, microcontrollers, simple Cloud APIs, and Internet of Things (IoT), we can certainly do better.

Qualifications: You will walk into an empty state-of-the-art optics lab that is just renovated. The lab will have HEPA filtering and a decent temperature stability spec, with metal ceiling tiles as poor-man's electromagnetic shielding. But just how good (or bad) is the lab environment under normal usage? To this end, your task is to build a distributed monitoring system with multiple multi-parameter sensors that pools the real-time environment data and upload them to the Cloud, and ideally with simple visualizations. This system, once finished, will continue to run for years if not decades, without needing major maintenance, and will provide extremely valuable data not only for the lab users but also for the building and facilities team at Physics (and even campus) when building or renovating future labs. You will learn to select sensors that probe temperature, humidity, pressure, air quality, sound, light, electromagnetic fields, and more (like these: https://www.adafruit.com/product/5046), to control them with Python and Bluetooth- or wifi-enabled microcontrollers (such that you can spread them out in the lab), to analyze the “big data” stream, and to upload it to the Cloud (like in here: https://learn.adafruit.com/gdocs-sensor-logging-from-your-pc). You will become an expert in reading spec sheets, soldering, embedded system control, and Cloud-based data visualization. If time permits, in addition to commercial sensors, we will also set up an optical interferometer with a position-sensitive detector, to correlate lab environment variations with optical path length/angle/position change. Finally, you will be part of an exciting journey of setting up a state-of-art optics/optoelectronics lab from scratch and get exposed to a wide variety of cool instruments. Required: motivation to spend the time and learn new skills, experience in reading spec sheets (https://en.wikipedia.org/wiki/Data_sheet), basic Python knowledge. Good to have: experience with sensors, microcontrollers, data science, Cloud APIs, or free-space optics

Weekly Hours: 6-8 hrs