  Fibers constitute the backbone of modern communication and are used in laser
surgeries; fibers also genarate coherent X-ray, guided-sound and
supercontinuum. In contrast, fibers for capillary oscillations, which are
unique to liquids, were rarely considered in optofluidics. Here we fabricate
fibers by water bridging an optical tapered-coupler to a microlensed coupler.
Our water fibers are held in air and their length can be longer than a
millimeter. These hybrid fibers co-confine two important oscillations in
nature: capillary- and electromagnetic-. We optically record vibrations in the
water fiber, including an audio-rate fundamental and its 3 overtones in a
harmonic series, that one can hear in soundtracks attached. Transforming
Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems
[MECS], boosts the device softness by a million to accordingly improve its
response to minute forces. Furthermore, MECS are compatible with water, which
is a most important liquid in our world.
