Now that we’ve closed the concept phase for the auto-stirring microwave bowl we would like to update you on our prototyping progress. Thanks for all the ideas that were submitted! After testing several concepts utilizing the spinning of the turntable as well as the heat generated by the microwave, we feel that we are gradually narrowing in on a direction to move forward with. In addition to the challenges identified in our last update (material limitations, food density, turntable strength) we have begun to focus our attention on product simplicity, manufacturing, price, ease of use, and cleaning, with a better understanding of functional limitations.
The first concept was an attempt to use the motion of the turntable to create a continuous wobbling effect when a bowl is placed on a plastic plate supported only by a single point in the center. The idea was that the contents of the bowl would be agitated gradually when placed on the wobble plate. While this concept consists of only a single part that can be used with a variety of bowls, it proved to be not very effective.
The possibility for harnessing the heat of the microwave seemed promising, so a device was prototyped that would float inside the bowl and use steam propulsion to drive mixing paddles. This prototype consists of a sealed floatation chamber and a separate volume where water can be stored with several ports for emitting steam. The thought was that the water would boil inside the microwave creating a teapot effect at each of the ports, spinning the mixing paddles. After testing, it took too long for the contained water to heat up and generated very little force.
The thought of just inserting a spoon or spatula into the bowl during turntable rotation was worth a try. A model was made with an articulating arm fixed to the interior of the microwave with a suction cup. The articulating arm is adjustable to accommodate a variety of bowl shapes. The end could potentially be detachable and interchangeable. This simple idea did not provide enough of a mixing effect.
Using bits of the previous prototype, we then created an array of paddles attached to the lid of a bowl that would turn when impacting a point held fixed with a suction cup. The wings at the top of each paddle could impact anywhere along their length allowing for some flexibility with suction cup placement. The results were promising so we decided to pursue this further and create a version with gear driven paddles that would spin more continuously.
The following video describes this concept in more detail:
After a conversation with the inventor Michelle B. last Friday, it was agreed to move forward with the geared paddle concept. In addition to mechanism refinement, we will be considering possibilities for optional paddle shapes that may be interchangeable for use with different types of food. Our goal for the short term will be to focus on a simple mechanical solution with a minimum number of parts made from microwave safe materials. In the long term we will continue to research other more advanced and technically challenging ways of stirring inside a microwave oven.
If you have any comments or suggestions, feel free to add them in the comments of this blog post.
