Aluminum foil (2021)
Points and comments are a snapshot, not live.
Kitchen aluminum foil's material properties and potential for self-replicating microfabrication.
Kragen Sitaker examines aluminum foil's remarkable properties: 10 μm thick, 88% reflectivity, 2.71 g/cc density, and cost under 50¢/m². It work-hardens rapidly, enabling origami and single-point incremental forming. The author demonstrates folding foil into cones that pierce apple skin, creating ribs that can stamp copies, and folding a foil crane. He explores applications in solar concentrators and suggests foil could be cut and folded into a 100,000-part self-reproducing matter compiler, speculating on electrolytic machining and anodization for tooling.
What commenters are saying
Commenters split between genuine appreciation and skeptical dismissal. One camp celebrates foil as a miracle material with no everyday alternative, while another dismisses the post as rambling about imaginary applications. A practical tip notes aluminum foil makes a great cheap light bounce for photography. Some commenters discuss existing metal folding techniques and 3D printing alternatives, sharing projects involving foil unwinding and embossing machines. The most substantive thread addresses the author's speculation about a 100,000-part foil matter compiler, with one commenter asking for a sketch and the author responding they have only a rough estimate.