My first week on the project was spent figuring out how to build my prototype. The piezo actuators needed are very expensive and difficult to use, but I found a good offer from Piezo Systems.
These actuators are probably not strong enough to create vibrations in a glass surface, but I think they're good enough to get started. Simple tactile experiments can also be done with the actuators directly on the skin, to see what it feels like. As these actuators need lots of voltage (±82V), I have to build an amplifier. That will be my next step.