hollowed shells

Chemically hollowed shells

This graphite shell, although it is only a few microns thick, withstood handling with tweezers. It was separated from its iron core by etching in hydrochloric acid.

origami on hollowed shell, partly disrupted by handling

Baking the isolated shell to over 1500˚C under vacuum does not smooth the creases.

Handling disturbs origami folds.