|Sponsors||K2 BioMicrosystems LLC.|
|Duration||Fall 2018 - Spring 2019|
We aim to design a self-contained, portable instrument for measuring and quantifying the turbidity of a solution over time by measuring the light scattered from the solution.
Optical scatterometry (otherwise known as turbidimetry or nephelometry) is a common way to determine the concentration of a contaminant, such as bacteria or proteins, in a solution. The nephelometry method detects the concentration of the solution by analyzing the amount of light that is scattered 90° to a laser shined into the solution, while turbidimetry measures the concentration using detectors 180° from the laser. Nephelometry is better used for low concentrations, while turbidimetry is better suited for high concentrations. These techniques requires expensive machinery that is not always portable, or user friendly.
- Touch Screen
- Wireless Charging Battery
- Production model Less than $200
- Point of Care: Negates need for central lab
- Affodable/Portable: Use in small clinics or developing countries
Fish and Wildlife
- On-site measurements: Stream/groundwater contaminant check
- Ease of use: Minimal training required
- Single PCB vs. Multiple PCB's
For initial testing we are using multiple PCB's, one for each photodiode and for the laser diode. However there are size constraints to consider and the three PCB's may be consolidated to one if it will save space.
- Laser Module vs. Laser Diode and Lens
A laser module would be easier to install, because it has the lens built in, however the laser diode and external lens will have a greater degree of accuracy when installing. For this reason, we have chosen to use the Laser Diode and external lens.
PhotoDiode Amplification Circuit
In order to amplify the current provided by the photodiode, a logarithmic amplifier will be used in order to normalize the values given by the photodiode. The chosen Logarithmic amplifier is the Analog Devices ADL5303. Using the shown schematic a PCB was created.
Laser Diode Circuit
The laser diode needs an amplification circuit and protection circuit in order to drive the laser at a specified light and to protect the laser diode from being damaged due to over voltage or over current. The IC-WJ laser driver chip has been chosen due to its watchdog protection circuitry.
The cuvette, which will hold the solution, will be placed in a 3D printed cuvette holder. The cuvette holder will have a hole in each side, to place 3 photodiodes and a laser diode into. All designs were done in TinkerCad. Several prototypes were made at University of Idaho facilities, before a final cuvette holder was printed from Shapeways. This design for a cuvette holder will be incorporated in the final design when a larger container will be 3D printed to hold all of the designed electronics.
||Jeremy Cram is a student in Electrical Engineering hoping to pursue a career communication networks/systems in western America.|
||Kodi Cumbo is a Computer Science and Electrical Engineering student with an interest in embedded systems. He plans to pursue a related career in the Puget Sound area after graduation.|
||Jeremiah Rodgers is an Electrical Engineering student with an interest in acoustics and signal processing. He plans on working for NavSea in Keyport, WA after graduation.|
||Weihang Wang is a student in Electrical Engineering with an interest in power system.He is hoping to pursue jobs in electrical company.|