I'm trying to make a very small (3x3 cm or less) cup or surface that will heat to around 200C. The surface needs to be dry and I only care about heating the surface and not any particular volume of air around it. Ideally this would be on fairly low voltage (nothing more than a 9V hopefully, or even possibly on a USB connection) so it could be semi-portable.
I don't have a lot experience with heating elements, so I'm not sure of the best way to do this. Is this even a feasible project? If so, are there any out of the box things I can buy that will do this? Or will I have to resort to something like fixing some nichrome or heating pads to ceramic and doing a lot of testing?
Additionally, are there any recommended ways of controlling the temperature of the surface? I was thinking of making some kind of PID control with a temperature sensor, but I'm sure there's a simpler and safer way.
Thanks for your help!