This model is made of paper, it can run on a bowl of hot water and ice up to 13 minutes. Top and bottom surfaces of heat exchanger are made of office paper reinforced with cardboard ribs, most of parts are soaked with superglue to achieve strength and water resistance.
Displacer is also made of office paper, and its drive is made in the form of oscillating frame, as it is not possible to make it as a conventional airtight vertical rod. Diaphragm is made of napkin covered with glue for rubber.
Assembly process: http://only-paper.ru/forum/38-20451-1