How to Build an Android: The True Story of Philip K. Dick's Robotic Resurrection, by David F. Dufty is about the creation of the Philip K. Dick android head, and how it vanished.
Two people are chiefly responsible for making the Philip K. Dick android head: David Hanson, a sculptor/animatronic artist who makes lifelike rubber heads, and Andrew Olney, a software engineer who worked on natural language tutorial software. They teamed up at the University of Memphis, and with barebones funding, they built a robot head that looked like the late science fiction writer. The head had a plastic skull (made on a 3D printer). Motors, pulleys, and wires were attached to the skull, and to a special rubber that Hanson had formulated called "frubber," which mimicked the elastic properties of human skin. Face recognition software and a camera mounted on the robot gave the PKD android the ability to lock eyes with humans it conversed with.
To give the android the gift of gab, Olney uploaded a massive database of PKD's novels and interviews into a databased, which indexed the content. When a person spoke with the android, one of its multiple computers translated the speech into text. Another computer queried the database and synthesized something for the PKD android to say. Another computer controlled the android's frubber face as it recited the words.
Dufty does fine job of on-the-ground storytelling, presenting the late night coding and soldering sessions, mad-scrambles to meet deadlines, small and major victories, and petty bureaucratic hassles that Hanson, Olnet, and their colleagues experienced over the course of a couple of years.
Many people familiar with the PKD head know that it disappeared after Hanson left it in the overhead bin on a flight he was on, and forgot all about it until he was out of the airport. When he remembered and contacted the airline, the head was gone. It has never been recovered.