Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional
Conducting Networks for a Highly Sensitive Noncontact Sensing Device
Yanlong Tai, Gilles Lubineau
King Abdullah University of
Science and Technology (KAUST), Physical Sciences and Engineering Division,
COHMAS Laboratory, Thuwal 23955-6900, Saudi Arabia
Abstract
Recently, flexible and transparent conductive films (TCFs) are
drawing more attention for their central role in future applications of
flexible electronics. Here, we report the controllable fabrication of TCFs for
moisture-sensing applications based on heating-rate-triggered, 3-dimensional
porous conducting networks through drop casting lithography of single-walled
carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate
(PEDOT:PSS) ink. How ink formula and baking conditions influence the
self-assembled microstructure of the TCFs is discussed. The sensor presents
high-performance properties, including a reasonable sheet resistance (2.1
kohm/sq), a high visible-range transmittance (> 69 %, PET = 90 %), and good
stability when subjected to cyclic loading (> 1000 cycles, better than
indium tin oxide
film) during processing, when formulation parameters are well optimized (weight
ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating
rate: 36 ℃/minute). Moreover, the benefits of these kinds of TCFs were
verified through a fully transparent, highly sensitive, rapid response, noncontact
moisture-sensing device (5×5 sensing pixels).
