A flexible humidity sensor based on KC–MWCNTs composites

Abstract Multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were dispersed in the biopolymer kappa-carrageenan (KC) to form a flexible composite via evaporative casting method. The glycerin was used as plasticizer to increase the flexibility of the composite. The KC—CNTs was examined by using FESEM and Raman, and then the humidity sensing properties of the samples were characterized under alternating current (AC). The purpose for using AC power supply is to avoid the possible polarization effect during measurements of the humidity properties. The experimental data exhibit that the fabricated sensors have high response to relative humidity (RH) with good repeatability, stability, and low hysteresis. A phenomenon that the impedance of the sensor decreases with ascending RH was also found and the basic sensing mechanisms were discussed.

[1]  Hongjie Dai,et al.  Carbon nanotubes: synthesis, integration, and properties. , 2002, Accounts of chemical research.

[2]  Dong Qian,et al.  Mechanics of carbon nanotubes , 2002 .

[3]  M. Dresselhaus.  Carbon nanotubes , 1995 .

[4]  S. A. Moiz,et al.  Humidity Sensing Properties of Carbon Nano-Tube Thin Films , 2011 .

[5]  J. Łukaszewicz,et al.  A novel carbon-based ionic conductor for humidity sensors , 2006 .

[6]  K. Nordtvedt.  from newton's moon to einstein's moon , 1996 .

[7]  Fanli Meng,et al.  Carboxylation multi-walled carbon nanotubes modified with LiClO4 for water vapour detection , 2004 .

[8]  Y. C. Chan,et al.  Fast response resistive humidity sensitivity of polyimide/multiwall carbon nanotube composite films , 2011 .

[9]  Young-Min Choi,et al.  Investigation of the humidity effect on the electrical properties of single-walled carbon nanotube transistors , 2005 .

[10]  R. Baughman,et al.  Carbon Nanotubes: Present and Future Commercial Applications , 2013, Science.

[11]  Litao Liu,et al.  Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis , 2009, Sensors.

[12]  P. Poncharal,et al.  Water-vapor effect on the electrical conductivity of a single-walled carbon nanotube mat , 2000 .

[13]  P. Feng,et al.  A novel compact design of calibration equipment for gas and thermal sensors. , 2011, The Review of scientific instruments.

[14]  Jonathan N. Coleman,et al.  Mechanical Reinforcement of Polymers Using Carbon Nanotubes , 2006 .

[15]  Zhaoxiong Xie,et al.  High-sensitivity humidity sensor based on a single SnO(2) nanowire. , 2007, Journal of the American Chemical Society.

[16]  Li-Rong Zheng,et al.  Flexible UHF Resistive Humidity Sensors Based on Carbon Nanotubes , 2012, IEEE Sensors Journal.

[17]  Ganna Kharlamova,et al.  Nanosensors in Systems of Ecological Security , 2015 .

[18]  Ming Ma,et al.  Capacitive humidity sensor based on amorphous carbon film/n-Si heterojunctions , 2010 .

[19]  John T.W. Yeow,et al.  Carbon nanotube-enhanced capillary condensation for a capacitive humidity sensor , 2006 .

[20]  Jing Wang,et al.  Structure Analysis of Humidity Sensing Composite of BaTiO3 and Polymer QAR , 2007 .

[21]  M. in het Panhuis,et al.  Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes , 2012, Beilstein journal of nanotechnology.

[22]  Tuo Li,et al.  Carbon nanotubes humidity sensor based on high testing frequencies , 2011 .

[23]  Douglas R. Kauffman,et al.  Carbon nanotube gas and vapor sensors. , 2008, Angewandte Chemie.

[24]  Jerzy P. Łukaszewicz.  Carbon Films for Humidity Sensors , 2006 .

[25]  Hyung-Gi Byun,et al.  Selected Peer-Reviewed Articles from the 8th Asian Conference on Chemical Sensors (ACCS 2009) , 2011 .

[26]  Bin Chen,et al.  Pore structure of raw and purified HiPco single-walled carbon nanotubes , 2002 .

[27]  Liang Fang,et al.  Humidity sensor based on multi-walled carbon nanotube thin films , 2011 .