Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Water Fibers   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.

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The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
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The categories of this paper are: eess
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
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The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat