Main Page
Welcome to the wiki page for the course PC5271: Physics of Sensors!
This is the repository where projects are documented. Creation of new accounts have now been blocked,and editing/creating pages is enabled. If you need an account, please contact Christian.
Deadline for report
Deadline for finishing your report on this wiki will be 29 April 2025 23:59:59 ;) Please be ensured you are happy with your project page at this point, as this will be the basis for our assessment. Thanks!! Ramanathan Mahendrian and Christian Kurtsiefer
Projects
Project 1 (Example)
Keep a very brief description of a project or even a suggestion here, and perhaps the names of the team members, or who to contact if there is interest to join. Once the project has stabilized, keep stuff in the project page linked by the headline.
Laser Gyroscope
Team members: Darren Koh, Chiew Wen Xin
Build a laser interferometer to detect rotation.
Laser Distance Measurer
Team members: Arya Chowdhury, Liu Sijin, Jonathan Wong
This project aims to build a laser interferometer to measure distances.
(CK: We should have fast laser diodes and fast photodiodes, mounted in optics bench kits)
Non-contact Alcohol Concentration Measurement Device At NIR Spectrum
Team members: Lim Gin Joe,Sun Weijia, Yan Chengrui, Zhu Junyi This project aims to build a sensor to measure the concentration of alcohol by optical method (CK: you can check Optics Letters 47, 5076-5079 (2022) https://doi.org/10.1364/OL.472890 for some info)
Ultrasonic Acoustic Remote Sensing
Team member(s): Chua Rui Ming
How well can we use sound waves to survey the environment?
(CK: we have some ultrasonic transducers around 40kHz, see datasheets below)
Blood Oxygen Sensor
Team members: He Lingzi, Zhao Lubo, Zhang Ruoxi, Xu Yintong
This project aims to build a sensor to detect the oxygen concentration in the blood.
(CK: We have LEDs at 940nm and 660nm peak wavelenth emission, plus some Si photodiodes)
Terahertz Electromagnetic Wave Detection
Team members: Shizhuo Luo, Bohan Zhang
This project aims to detect Terahertz waves, especially terahertz pulses (This is because they are intense and controllable). We may try different ways like electro-optical sampling and VO2 detectors.
Optical measurement of atmospheric carbon dioxide
Team member(s): Ta Na, Cao Yuan, Qi Kaiyi, Gao Yihan, Chen Yiming
This project aims to make use of the optical properties of carbon dioxide gas to create a portable and accurate measurement device of carbon dioxide.
Photodetector with wavelength @ 780nm and 1560nm
Team members: Sunke Lan
To design photodetector as power monitor with power within 10mW.
(CK: Standard problem, we have already the respective photodiodes)
Single photon double-slit interference
Team members: Cai Shijie, Nie Huanxin, Yang Runzhi
1.Build a single photon detector using LED. The possible LED is gallium compounds based, emitting wavelength around 800nm(red light).
2. Other possible detector: photomultiplier or avalanche photon detector(do we have that?).
3.Do single double-slit interference experiment.
Other devices needed: use LED as single photon source (wavelength shorter than the emitting wavelength 800nm)
prove the detection is single photon: need optical fibre, counting module
STM32-Based IMU Attitude Estimation
Team members: Li Ding, Fan Xuting
This project utilizes an STM32 microcontroller and an MPU6050 IMU sensor to measure angular velocity and acceleration, enabling real-time attitude angle computation for motion tracking.
Fluxgate magnetometer
Team members: Ni Xueqi
This project uses the fluxgate magnetometer to quantify the magnitude of an external magnetic field generated through coils with varying currents and permanent magnets with varying distances.
CO2 Concentration Detector
Team members: Xie Zihan，Zhao Yun，Zhang Wenbo
Infrared absorption-based CO₂ gas sensors are developed based on the principle that different substances exhibit different absorption spectra. Because the chemical structures of different gas molecules vary, their degrees of absorption of infrared radiation at various wavelengths also differ. Consequently, when infrared radiation of different wavelengths is directed at the sample in turn, certain wavelengths are selectively absorbed and thus weakened by the sample, generating an infrared absorption spectrum.
Once the infrared absorption spectrum of a particular substance is known, its infrared absorption peaks can be identified. For the same substance, when the concentration changes, the absorption intensity at a given absorption peak also changes, and this intensity is directly proportional to the concentration. Therefore, by detecting how the gas alters the wavelength and intensity of the light, one can determine the gas concentration.
Light Sensing System Based on the Photoelectric Effect
Team members: Xu Ruizhe, Wei Heyi, Li Zerui, Ma Shunyu
This project utilizes the principle of the photoelectric effect to design a smart light sensing system. The system can detect ambient light intensity and process the data using Arduino or Raspberry Pi. When the light intensity changes beyond a predefined threshold, the system can trigger responses such as lighting up an LED, activating a buzzer, or automatically adjusting curtains.
Temperature and humidity sensors
Team members: Chen Andi, Chen Miaoge, Chen Yingnan, Fang Ye
This project aims to develop a simple temperature and humidity monitoring system using the DHT11 sensor and an Arduino microcontroller, with real-time data displayed on an electronic screen. The system is powered by a 9V battery, making it portable and suitable for various environmental monitoring applications. In addition to the DHT11 sensor, the B57861S-SHT31 sensor is also integrated into the system to measure temperature and humidity simultaneously. By comparing the data obtained from both sensors under the same environmental conditions, this project can analyze differences in measurement accuracy, stability, and response time.
(working now)
By integrating the sensors with the Arduino board and displaying the measurements on a screen, this project demonstrates a practical approach to building low-cost, efficient environmental monitoring devices. The project also serves as a basic prototype for further development in smart home systems, weather stations, and IoT applications.
Ultrasonic Doppler Speedometer
Team members: Yang Yuzhen, Mi Tianshuo, Liu Xueyi, Shao Shuai
Design and build an ultrasonic Doppler speedometer to measure the velocity of a moving object.
Resources
Books and links
- A good textbook on the Physics of Sensors is Jacob Fraden: Handbook of Mondern Sensors, Springer, ISBN 978-3-319-19302-1 or doi:10.1007/978-3-319-19303-8. There shoud be an e-book available through the NUS library at https://linc.nus.edu.sg/record=b3554643
Software
- Various Python extensions. Python is a very powerful free programming language that runs on just about any computer platform. It is open source and completely free.
- Gnuplot: A free and very mature data display tool that works on just about any platform used that produces excellent publication-grade eps and pdf figures. Can be also used in scripts. Open source and completely free.
- Matlab: Very common, good toolset also for formal mathematics, good graphics. Expensive. We may have a site license, but I am not sure how painful it is for us to get a license for this course. Ask if interested.
- Mathematica: More common among theroetical physicists, very good in formal maths, now with better numerics. Graphs are ok but can be a pain to make looking good. As with Matlab, we do have a campus license. Ask if interested.
Apps
Common mobile phones these days are equipped with an amazing toolchest of sensors. There are a few apps that allow you to access them directly, and turn your phone into a powerful sensor. Here some suggestions:
- Physics Toolbox sensor suite on Google play store or Apple App store.
Data sheets
A number of components might be useful for several groups. Some common data sheets are here:
- Photodiodes:
- Generic Silicon pin Photodiode type BPW34
- Fast photodiodes (Silicon PIN, small area): S5971/S5972/S5973
- PT 100 Temperature sensors based on platinum wire: Calibration table
- Thermistor type B57861S (R0=10kΩ, B=3988Kelvin). Search for Steinhart-Hart equation. See Thermistor page here as well.
- Humidity sensor
- Sensirion device the reference unit: SHT30/31
- Thermopile detectors:
- G-TPCO-035 / TS418-1N426: Thermopile detector with a built-in optical bandpass filter for light around 4μm wavelength for CO2 absorption
- Resistor color codes are explained here
- Ultrasonic detectors:
- plastic detctor, 40 kHz, -74dB: MCUSD16P40B12RO
- metal casing/waterproof, 48 kHz, -90dB, MCUSD14A48S09RS-30C
- metal casing, 40 kHz, sensitivity unknown, MCUST16A40S12RO
- metal casing/waterproof, 300kHz, may need high voltage: MCUSD13A300B09RS
- Magnetic field sensor
- Fluxgate magnetometer FCL100
- Lasers
- Red laser diode HL6501MG
- Generic amplifiers
Some wiki reference materials
Old Wiki
You can find entries to the wiki from AY2023/24 Sem 2
