Upgrade your D&D game with Rainbow Shop CN’s beautiful shimmery electroplated metal dice. Made from zinc alloy, they have a nice heft to them, and you’ll get a full set including D20, D12, D10, D10(percentile), D8, D6, and D4 for all your gaming needs.
Adafruit shows us how to make an electronic and portable dice roller. It uses a small motor to spin a small platform, which in turn rolls the dice. As others have pointed out, it would be better if you make the platform uneven to shake the dice even more. Full guide here.