I was doing experiments in the electronics kit today and came to the experiment that demonstrates how a ceramic microphone can be utilized to generate electrical current in a wire by capturing sound. As I was reading the chapter, I went for a walk with my dog.
Idea #1 - I began to think - couldn't this idea be utilized to create quieter motors that are also more energy efficient? By encapsulating a noisy (high friction) motor in a dual-wall casing designed to capture sound waves and generate electricity, you could rectify the output and capture into battery storage. Perhaps even noise reducing walls could be created that do the same thing. The output of the walls or anything that isn't 'enclosing' would probably be pretty minimal because of the radiant nature of sound waves. Actually designing the enclosure for capturing and converting sound is probably quite an engineering chore because of the synchronicity required in the enclosure itself. The whole device would have to expand/contract in unison. This line of thinking led to idea #2
Idea #2 - I began to think about radiant energy capture. Solar energy is a pretty good example of this problem. Solar cells are notoriously inefficient, I think because they are capturing solar energy in one small angular channel. After all, the energy coming from the sun is radiating from a giant source, in multiple directions at once. I started thinking about polarizers and what happens to the light that doesn't pass through the polar filter. If it is reflected, couldn't solar cells be designed with a reflection/capture system that aims the reflected energy to a single focus point for capture/conversion?
That's it - just wanted to write those down before I forgot them.