  We discuss the response of biopolymer filament bundles bound by transient
cross linkers to compressive loading. These systems admit a mechanical
instability at stresses typically below that of traditional Euler buckling. In
this instability, there is thermally-activated pair production of topological
defects that generate localized regions of bending -- kinks. These kinks
shorten the bundle's effective length thereby reducing the elastic energy of
the mechanically loaded structure. This effect is the thermal analog of the
Schwinger effect, in which a sufficiently large electric field causes
electron-positron pair production. We discuss this analogy and describe the
implications of this analysis for the mechanics of biopolymer filament bundles
of various types under compression.
