  Metal meshes have emerged as an important class of flexible transparent
electrodes. We report on the characteristics of a new class of asymmetric
meshes, tiled using a recently-discovered family of pentagons. Micron-scale
meshes were fabricated on flexible polyethylene terephthalate substrates via
optical lithography, metal evaporation (Ti 10 nm, Pt 50 nm) and lift-off. Three
different designs were assessed, each with the same tessellation pattern and
linewidth (5 micron), but with different sizes of the fundamental pentagonal
unit. The designs corresponded to areal coverage of the metal patterns of 27%
(Design#1), 14% (Design#2) and 9% (Design#3), respectively. Good mechanical
stability was observed for both tensile strain and compressive strain. After
1,000 bending cycles, devices subjected to tensile strain showed fractional
resistance increases in the range 8% to 17% with the lowest changes observed
for Design#2. Devices subjected to compressive strain showed fractional
resistance increases in the range 0% to 7% with best results observed for
Design#1. The performance of the pentagonal metal mesh devices as visible
transparent heaters via Joule heating was also assessed. A saturation
temperature of 88 +/- 1 degrees C was achieved at low voltage (5 V) with a fast
response time (~ 20 s) and a high thermal resistance (168 +/- 6 degrees C
cm2/W). Finally, de-icing was successfully demonstrated (45 s at 5 V) for an
ice layer on a glass coupon placed on top of the PET substrate.
