The influence of bending on the performance of flexible carbon black/polymer composite gas sensors

The performance of electronics on flexible substrates suffers under substrate bending leading to reduced device performance. In this article, we highlighted the influence of bending strain on a conductive polymer composite gas sensor and developed a model to investigate the influence of strain. We evaluated the strain influence on the resistance of a gas sensor with respect to sensitivity, filler content, cyclic loading, and electrode orientation. The sensitivity of gas sensors increased with decreasing tensile bending radii. The influence of strain was dominant for gas sensors with less carbon black concentration. Cyclic bending tests showed a decrease of sensor resistance versus time and a plastic deformation. A sensor geometry orientations effect to reduce the sensitivity to bending strain was achieved by aligning the electrode fingers parallel to the strain. A model was successfully implemented to simulate strain influences inside the polymer incorporating the Poisson ratio. We suggest a concept to achieve a strain insensitive gas sensor by creating an orientation between single particles inside the composite. Implementing this results into existing gas sensors will improve the measurement quality and reliability of sensors on flexible substrates. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013

[1]  Michael C. McAlpine,et al.  Silk‐Based Conformal, Adhesive, Edible Food Sensors , 2012, Advanced materials.

[2]  S. Chua,et al.  A mechanical assessment of flexible optoelectronic devices , 2001 .

[3]  P. Osterrieder,et al.  A finite element model for impact simulation with laminated glass , 2007 .

[4]  D.D.L. Chung,et al.  TECHNICAL NOTE: A piezoresistive carbon filament polymer-matrix composite strain sensor , 1996 .

[5]  Carbon Black Reinforced Epoxy Resin Nanocomposites as Bending Sensors , 2009 .

[6]  M. Knite,et al.  Polyisoprene-carbon black nanocomposites as tensile strain and pressure sensor materials , 2004 .

[7]  John P. Dear,et al.  The mechanical behaviour of poly(vinyl butyral) at different strain magnitudes and strain rates , 2012, Journal of Materials Science.

[8]  K. Naskar,et al.  Dielectric relaxation behavior of conducting carbon black reinforced ethylene acrylic elastomer vulcanizates , 2012 .

[9]  Jungyoup Han,et al.  A flexible polymer tube lab-chip integrated with microsensors for smart microcatheter , 2008, Biomedical microdevices.

[10]  Xiaoming Tao,et al.  Investigation of carbon black/silicone elastomer/dimethylsilicone oil composites for flexible strain sensors , 2012 .

[11]  Q. Zheng,et al.  Improvement of gas sensing performance of carbon black/waterborne polyurethane composites: Effect of crosslinking treatment , 2006 .

[12]  Q. Zheng,et al.  Time dependence of piezoresistance for the conductor-filled polymer composites , 2000 .

[13]  G. Tröster,et al.  Testing of flexible InGaZnO-based thin-film transistors under mechanical strain , 2011 .

[14]  Christoph Zysset,et al.  Woven Thin-Film Metal Interconnects , 2010, IEEE Electron Device Letters.

[15]  C. Gallo,et al.  Classical Electrostatic Description of the Work Function and Ionization Energy of Insulators , 1976, IEEE Transactions on Industry Applications.

[16]  T. Someya,et al.  Stretchable active-matrix organic light-emitting diode display using printable elastic conductors. , 2009, Nature materials.

[17]  T. Someya,et al.  A Rubberlike Stretchable Active Matrix Using Elastic Conductors , 2008, Science.

[18]  L. Chen,et al.  Piezoresistive Behavior Study on Finger‐Sensing Silicone Rubber/Graphite Nanosheet Nanocomposites , 2007 .

[19]  J. Rogers,et al.  Stretchable Electronics: Materials Strategies and Devices , 2008 .

[20]  E. Smela,et al.  Stretchable Electrodes with High Conductivity and Photo‐Patternability , 2007 .

[21]  Longitudinal and transverse strain sensitivity of gold film , 1987 .

[22]  M. Raza,et al.  Effect of nanosized carbon black on the morphology, transport, and mechanical properties of rubbery epoxy and silicone composites , 2012 .

[23]  T. Someya,et al.  Stretchable, Large‐area Organic Electronics , 2010, Advanced materials.

[24]  G. Helgesen,et al.  Individual strings of conducting carbon cones and discs in a polymer matrix: Electric field‐induced alignment and their use as a strain sensor , 2012 .

[25]  Christian M. Siket,et al.  Arrays of Ultracompliant Electrochemical Dry Gel Cells for Stretchable Electronics , 2010, Advanced materials.

[26]  Lingyan Wang,et al.  Molecularly mediated thin film assembly of nanoparticles on flexible devices: electrical conductivity versus device strains in different gas/vapor environment. , 2011, ACS nano.

[27]  Minbaek Lee,et al.  Flexible Nanocomposite Generator Made of BaTiO3 Nanoparticles and Graphitic Carbons , 2012, Advanced materials.

[28]  Yonggang Huang,et al.  Materials and Mechanics for Stretchable Electronics , 2010, Science.

[29]  K. West,et al.  Highly Stretchable and Conductive Polymer Material Made from Poly(3,4‐ethylenedioxythiophene) and Polyurethane Elastomers , 2007 .

[30]  Y. S. Kim.  Influence of carbon black content and film thickness on vapor detection properties of polyvinylpyrrolidone composite sensors , 2010 .