Anyone know what material the mirrors are made from? I'm surprised that the configuration is a horizontal device with the mirrors vertical, I'd assume a vertica

Anyone know what material the mirrors are made from? I'm surprised that the configuration is a horizontal device with the mirrors vertical, I'd assume a vertical device would be easier. Edit: hmm, on second thought, a vertical device would have the electrode vertical as well and it's probably metal. Maybe a polysilicon electrode?