Electrostatic Gating in Carbon Nanotube (CNT) Networks Using Scanning Gate Microscopy

POSTER

Abstract

Carbon Nanotube (CNT) field effect transistor aptasensors show promise for biosensing applications because of their sensitivity to electrical changes in the environment at the molecular level. Previous work using a biased atomic force microscope (AFM) tip to electrostatically gate specific locations in the network demonstrated that individual metallic-semiconducting junctions were sensing hotspots. To better understand the role of these junctions within the context of the entire network morphology, we created a scanning gate microscopy setup using a conductive AFM tip as a movable, localized gate and an electronic measurement system to track the network current. The change in device current is measured using a multichannel lock-in amplifier as the conductive tip of fixed bias and height is scanned over the network. The resulting data reflects the response of the network to specific network locations being gated. We combine the conductance data with the topographic AFM image to create a conductive map which can reveal regions of higher network sensitivity. We have successfully created a scanning gate microscopy system at Cal Poly making it possible to map the electrical sensitivity across the entire CNT network to localized gating.

Authors

  • Savannah Silva

    California Polytechnic State University

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India