In engineering, a deployable structure is one that can change shape in a way that greatly alters its size — large-scale examples include scissor lifts and bouncy castles. Conventional deployable structures are transformed into a larger shape through the extension of linkages (as in scissor lifts) or by inflation (bouncy castles). Both types of structure are then secured into their new shape by an external agent: a lock and the sustained application of air pressure, respectively. However, neither can secure themselves. This new approach I write about, does just that.