Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tree frog-inspired nanopillar arrays for enhancement of adhesion and
  friction   Bioinspired structure adhesives have received increasing interest for many
applications, such as climbing robots and medical devices. Inspired by the
closely packed keratin nanopillars on the toe pads of tree frogs, tightly
arranged polycaprolactone nanorod arrays are prepared by mold process and
chemical modification. Nanorod arrays show enhanced adhesion and friction on
both smooth and rough surfaces compared to the arrays with hexagonal
micropillars. The bonding of nanorods results in a larger stiffness of the
nanorod surface,contributing mainly to friction rather than adhesion. The
results suggest the function of closely packed keratin nanopillars on the toe
pad of tree frogs and offer a guiding principle for the designing of new
structured adhesives with strong attaching abilities.

30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph