A little kitchen science ended with a new approach to microwave cooking for the Boston-based firm Fractal Antenna Systems, Inc. Using a microwave oven to investigate properties of metamaterials, FRACTAL's researchers found that a layer of doily-like conductive cutouts could evenly distribute the microwaves and remove the hotspots that plague microwave cooking.
"Early microwave ovens worked quite well", noted co-inventor Nathan Cohen," but when cheaper designs made these a kitchen appliance it compromised on cooking evenly. This limits what you can cook and how well you can cook it. The food industry has been seeking a solution for years."
The innovation comes from the marriage of two exotic science applications-fractals and metamaterials. Fractals are intricate shapes built up by repeated applications of a simpler one, while metamaterials are composites made from close-spaced resonant shapes. By making the resonators out of fractals, the firm introduced a synergy that allowed a versatility of control and performance not achievable by other means. The firm calls these "metafractals". Added Cohen, " Think of it as an electric blanket for food, with nothing to plug in. The food can be placed on it or wrapped by it and get smooth cooking all around if desired, or focus on certain portions."
Built on a thin plastic sheet or into a serving tray, the metafractal solution "looks like a plastic wrap with a decorative pattern, but each of the doily-like pieces is a fractal that acts as a wireless resonator that picks up the microwaves from the microwave's 'klystron' and distributes it. The invention is thus passive, totally safe and is inexpensive to implement. It's a natural to include in the in-microwave packaging of a ready to cook meals.
An added "green" benefit of the metafractal solution is that the even-cooking cuts down the cooking time, saving energy. "A microwave is a power-hungry device, so cutting back how long you cook saves money, time, and carbon emissions", commented Cohen.
Based on patented and patent pending technology, the firm continues development based on feedback from the food industry. "Innovation means getting out of the laboratory, getting into the kitchen, and listening to the end-user, who will soon be our partners in this." The firm expects the metafractal solution to be available in consumer products within the next two years.