Team:Thessaloniki/Hardware
iGEM Thessaloniki
@iGEMthessaloniki
igem.thessaloniki
Hardware
Overview
Description
| Function
The device, designed by our dry lab, should be able to perform the following:- 1) Sets the temperature and light conditions for the time period selected by the user, in order for the amplification’s reactions to occur (if selected by the user).
- 2) Maps the wells of the testing plate and the biological material contained in them, so that it will provide a detailed chart of fluorescence measurements corresponding to certain wells.
3) Sets the temperature and light conditions specified by the user as well as a chronometer for the system reactions to occur and for the fluorescence to be measured.- 4) Receives the information and with digital image processing measures the quantity of fluorescence to finally present the results in a form of a plate-chart (as specified in 2).
| For Users
The device should provide the following to the users:- 1) Plug-and-Play: the device should be able to operate via a PC, with a USB port.
- 2) Graphical Interface: for the mapping of the plate and the user update concerning the temperature and light conditions.
- 3) Data: temperature, light, time, measurements, graphs containing all of the former and lastly the conclusion of whether the patient needs further examination or not.
Design: Circuit
Concerning our circuit, we designed two systems. The first system is responsible for maintaining the temperature in the desired range. The second system, based on the iGEM Aachen 2014 circuit, “measures” the fluorescence.
| First System
For temperature control, an Arduino Uno is used for controlling a Peltier device and a temperature sensor. The sensor reads the temperature and adjusts the voltage across the Peltier device, in reality, the Arduino generates a PWM pulse that activates and deactivates the Peltier, and the higher the frequency of the pulse the higher the temperature. The frequency of the pulse is adjusted based on the reading of the temperature sensor. For the precision of this system to be as high as possible, we implemented a PID controller using the Arduino PID library.
| Second System
The second system, which is implemented on a Raspberry Pi, keeps a timer for when the reaction is complete, then, an array of blue LEDs are lighted for a brief moment. Then a digital camera with an optical filter takes a frame of the fluorescent solution.
Fig.1 Temperature ControllerDesign: 3D Prototyping
Using TinkerCad, open-source software, our dry lab team created a 3D model of the mechanical part of the device. A screenshot of the device is displayed below:
Fig.2 3D CAD DesignAnalytical explanation of the key parts - 3D Device Prototyping - Right Side in Section:
- 1. Hardware Floor: this section contains the majority of the hardware material (computational units and camera)
- 2. Toehold’s Floor: this section contains the biological material and a part of the hardware (light source and temperature controllers)
- 3. Nest: detachable drawer that contains the plate with the biological material and the heater. The end position is measured and constructed in such a way for the biological material to match the camera frame.
- 4. Light Case: it contains the light source (LED), essential for the measurement of the fluorescence. It is constructed specifically to reduce the amount of light heading directly towards the camera but to permit light emission towards the plate.
- 5. Cable Holes: their purpose is to enable the connection of the two floors and of the device to an exterior computational unit (PC)
- 6. Camera Hole: this is covered by the protective narrow band filter of the camera and acts as a porch for the camera.
Learn More:
Model
Resources Table
Future Challenges
~ We have completed the first step towards the construction of a fully functional fluorometer device: the electrical and mechanical design (circuit and 3D).
~ The second remaining step would be the programming of the device aka the software, which will provide the graphical interface, the control of the key-components of the circuit, as well as the digital image processing for the quantification of the fluorescence.
~ Therefore, we have set the foundations for a plug-and-play fluorometer device, but there is more to be done in the future, considering the implementation of the designs. The software of the device is still a step that hasn’t been implemented since it concerns the future potential of the device in mass production scenarios.
~ The second remaining step would be the programming of the device aka the software, which will provide the graphical interface, the control of the key-components of the circuit, as well as the digital image processing for the quantification of the fluorescence.
~ Therefore, we have set the foundations for a plug-and-play fluorometer device, but there is more to be done in the future, considering the implementation of the designs. The software of the device is still a step that hasn’t been implemented since it concerns the future potential of the device in mass production scenarios.
Summary
Concluding, our team designed the electrical and mechanical parts of a fluorometer device, willing to model and to explore the potentials of its diagnostic tool, as well as the possible production and usage of the former, in diagnostic centers.