With the electronics specially, I didn't get much sleep. 4 Sonar Sensors, an Arduino, many many wires, resistors, transistors, a 12 volt power supply, 12 LED strips, etc. And a ton of Steve Daniels' help...
So the final material in which the structure was built in was Masonite (spll). There is a photo of me with a gig-saw slowly putting this thing together.