Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast humidity sensor based on liquid phase exfoliated graphene   Humidity sensing is important to a variety of technologies and industries,
ranging from environmental and industrial monitoring to medical applications.
Although humidity sensors abound, few available solutions are thin,
transparent, compatible with large-area sensor production and flexible, and
almost none are fast enough to perform human respiration monitoring through
breath detection or real-time finger proximity monitoring via skin humidity
sensing. This work describes chemiresistive graphene-based humidity sensors
produced in few steps with facile liquid phase exfoliation (LPE) followed by
Langmuir-Blodgett assembly that enables active areas of practically any size.
The graphene sensors provide a unique mix of performance parameters, exhibiting
resistance changes up to 10% with varying humidity, linear performance over
relative humidity (RH) levels between 8% and 95%, weak response to other
constituents of air, flexibility, transparency of nearly 80%, and response
times of 30 ms. The fast response to humidity is shown to be useful for
respiration monitoring and real-time finger proximity detection, with potential
applications in flexible touchless interactive panels.

31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph