I'm currently working on a project that involves switching a large heat pad with a 5v solid state relay, a sharp IR proximity sensor and arduino to switch the relay. Basically what I want to do is use the heat pad as a mechanism to heat a sheet of paper with thermochromic ink, it reacts at 27 degrees celcius. The problem I'm facing is that I need to secure the sheet of paper that has the thermo ink on it to the heat pad without any air gaps so as none of the heat dissapating from the heat pad heats the sheet(thermo) on top of it evenly. I'm not sure but I suppose I'm looking for a thermal adhesive tape. A tape that conducts heat well. Essentially I want this tape to be double sided so I can stick it to the heat pad but I can then stick the paper with thermo ink on it to the tape, so essentially there are three layers of materials. The heat pad, the thermal adhesive tape and the paper with thermo ink on it.
I'm not sure but I was looking at something like this
Any suggestions would be greatly welcome