  Inexpensive, portable lab-on-a-chip devices would revolutionize fields like
environmental monitoring and global health, but current microfluidic chips are
tethered to extensive off-chip hardware. Insects, however, are self-contained
and expertly manipulate fluids at the microscale using largely unexplored
methods. We fabricated a series of microfluidic devices that mimic key features
of insect respiratory kinematics observed by synchrotron-radiation imaging,
including the collapse of portions of multiple respiratory tracts in response
to a single fluctuating pressure signal. In one single-channel device, the flow
rate and direction could be controlled by the actuation frequency alone,
without the use of internal valves. Additionally, we fabricated multichannel
chips whose individual channels responded selectively (on with a variable,
frequency-dependent flow rate, or off) to a single, global actuation frequency.
Our results demonstrate that insect-mimetic designs have the potential to
drastically reduce the actuation overhead for microfluidic chips, and that
insect respiratory systems may share features with impedance-mismatch pumps.
