Photostimulated contraction
of MTs/kinesin-1 network inside a millifluidic
device (SI, Video S10). (A) Schematic representation
of the millifluidic device highlighting the area illuminated with
discontinuous microscope light. Taxol-stabilized MTs are mixed with
kinesin-1 motors and a preilluminated energy module prior to injection
into a millifluidic channel. (B,C) Over time, as available ATP in
the energy module is consumed by force-generating kinesin-1 motors,
discontinuous microscope illumination compensates for ATP consumption
and filamentous network contracts up to 38%. Quantitative analysis
of the width of the contracted network in the illuminated region shows
an exponential decay over time. The initial width of the network is W = 1.5 mm. (D) Space-time plot demonstrating the network
contraction along the white dashed line drawn in part C. (E) In the
nonilluminated areas, where ATP is only consumed but not replenished,
we monitored a reduced contractility of up to 10% after 1 h.