Final Design

        A user would first place a sample slide on top of the ceramic heater. The heater will be placed on an insulating piece made of delrin, to prevent any issues with high temperatures affecting the rest of the system. The ceramic heater would drive the temperature levels to the appropriate levels, and the cooling would be provided through convection via the 99 cfm fan. A closed-loop feedback system will be monitored by a thermocouple that is built into the ceramic heater that will send temperature data to the arduino board and then be sent to a personal computer. The arduino board is coded with a program that accurately controls the heating and cooling cycles, creating a reliable system that can perform a pcr reaction that a standard laboratory type thermal cycler would perform.

        Ultimately, the reduction in size of the portable thermal cycler is significant compared to the size of a conventional thermal cycler. The final design of the project would accept a single slide to be tested. The size of the final prototype is 11 cm x 9 cm x 24 cm, making it a very portable machine. 

Project Components

Results

Figure 2: Temperature vs. Time Graph

        As seen in the graph above, the thermal cycler is able to ramp up and dwell at a given temperature accurately. With the current configuration, the thermal cycler is able to achieve a heating ramp rate of 5°C/s and a cooling rate of 1°C/s.

The final prototype is estimated to cost about $800 (including material and machining costs) and about $990 after shipping fees.