  The existence of a crumpled phase for self-avoiding elastic surfaces was
postulated more than three decades ago using simple Flory-like scaling
arguments. Despite much effort, its stability in a microscopic environment has
been the subject of much debate. In this paper we show how a crumpled phase
develops reliably and consistently upon subjecting a thin spherical shell to
active fluctuations. We find a master curve describing how the relative volume
of a shell changes with the strength of the active forces, that applies for
every shell independent of size and elastic constants. Furthermore, we extract
a general expression for the onset active force beyond which a shell begins to
crumple. Finally, we calculate how the size exponent varies along the crumpling
curve.
