• The Simulated Chewing Simulator (SCA) is capable of mimicking the oral conditions of the mouth onto four 25 mm diameter samples

• The SCA can discretely dispense 33 mL/s of fluid to submerge the samples and drain at user-specified rates.

• The SCA can apply a downward force of 25 N onto the samples, with an option for the user to switch the surface pressing on the samples.

The first prototype focused on designing a beginning user interface, frame, and fluid system. The main fluid system consisted of a starting tank, a solenoid valve to control flow, a splash zone holding one 10 mm diameter sample, and an open drain tank. The system relied on gravity to move the fluid over the sample. The user interface consisted of two rotary encoders to set the cycle rate and timer, and two buttons for start and stop.

The prototype was capable of dispensing fluid without leaking at discrete intervals with a continuous drain. Several improvements were required to meet various user needs, including a chewing mechanism, discrete drainage, and holding multiple samples

The second prototype focused on achieving both the chewing and fluid flow conditions of the mouth. Two pumps were used to push fluid in/out of a central splash zone and an external tank. The added rack and pinion applied 25N of force using a flat plate onto the samples between fluid flow. Finally, the touch screen allowed the user to select a timer, fluid cycle rate, and chews/cycle, with a start, stop, and pause button.

The second prototype achieved most of the user requirements of applying forces and fluid to dental samples, working for an extended period of time without user input, and holding multiple samples. However, more improvements were required: holding 25 mm samples instead of 10 mm samples, having samples pressed on each other rather than a flat plate, and an improved gasket to better seal the splash zone.

The final design contained the same core functions as prototype 2, but included new additions to the frame, sample holder, user interface, and sealing system. Each of these additions improved the usability and safety of the device. 

The final design was capable of holding larger samples, applying force to press samples together, and submerging samples in discrete intervals. The SCA was able to run for two hours continuously without incident. Future improvements would be to replace the chewing mechanism motor with a stronger motor, allowing the system to reach 50N rather than 25N, which was a user need that wasn't feasible within the time and monetary limits.