Cellulose Paper Based Sensors
- 1. Cellulose paper based sensors Jin-Woo Han & M. Meyyappan Oct. 16 2012 ARCTek3
- 2. Advantages of paper based sensors nsors fabricated on a paper gas sensor, chemical detector, bio sensor, and strain gauge tures Flexible, bendable, foldable Bio-degradable: green technology Robust in cryo-temperatures role-to-role printing or ink-jet printing process Extremely cheaper than solid-state sensors: disposable SA Applications Biomedical sensor, single-time use sensor etection of structural defects and cracks, structural health monitoring Commercial:Intelligent packaging, advertising banner, newspaper ARCTek3
- 3. Example: humidity/water vapor sensing 2 1.8 1.8 RH= RH=10% RH=10% 10% 1.6 1.6 Conductance (µ S) Conductance (µ S) 1 Current (µ A) CNT on paper 1.4 30% 1.4 0 50% 40% 50% Bare paper 1.2 1.2 -1 1.0 60% 1.0 -2 60% 0.8 -1 0 1 0 50 100 150 200 250 -40 0 40 80 120 160 200 Voltage (V) Time (sec) Time (min) The chemical reaction between H 2O and CNT surface changes the conductivity of CNT according to the relative humidity. ARCTek3
- 4. Example: displacement(strain) gauge CNT Paper Flat state Tensile stress Compressive stress -less conductive -more conductive 1.2 Early stage 120 Steady stage 1.0 Conductance (nS) Conductance (µ S) 100 0.8 80 0.6 60 0.4 40 0.2 20 0 2 4 6 8 10 100 105 110 Frequency (#) Frequency (#) After stabilization, the connectivity with neighboring CNTs changes the conductivity of CNT according to the bending curvature. ARCTek3