title: Imaging of soft material with carbon nanotube tip using near-field scanning microwave microscopy.
abstract: In this manuscript, a near-field scanning microwave microscope (NSMM) of our own design is introduced while using a multi-walled carbon nanotube (MWCNT) bundle as the tip (referred to as 'CNT tip'). Clear images of gold-patterned numbers, photoresist stripes and corneal endothelial cells (cell line B4G12) were obtained by mapping the resonant frequency fr and S11 amplitude of a given area while the NSMM is operating in tapping mode. The CNT tip helps to improve image quality and reveals more information about the sample as compared to a traditional metallic tip. The CNT tip is flexible and does not scratch the surface of the sample during the scan, which is useful for imaging soft material in biological science. In the imaging of the B4G12 endothelial cells, the nuclei and cytoplasm can be clearly distinguished from the rest of the cell and its surrounding medium.
authors.affiliation: Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542, Singapore; National Laboratory for Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, PR China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore.
authors.forename: Wei-Qiang
authors.initials: WQ
authors.lastname: Sun
authors.affiliation: Key Laboratory for Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Feng
authors.affiliation: Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Shawn Wenjie
authors.initials: SW
authors.lastname: Tang
authors.affiliation: Key Laboratory for Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Physics & Tsinghua-Foxconn Nanotechnology Research Centre, Tsinghua University, Beijing 100084, PR China.
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Jiang
authors.affiliation: Key Laboratory for Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, PR China. Electronic address: xusy@pku.edu.cn.
authors.forename: Sheng-Yong
authors.initials: SY
authors.lastname: Xu
authors.affiliation: Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542, Singapore. Electronic address: phyongck@nus.edu.sg.
authors.forename: Chong Kim
authors.initials: CK
authors.lastname: Ong
mesh_terms: D002478:Cells, Cultured; D042783:Endothelial Cells / Q000648:ultrastructure; D004728:Endothelium, Corneal / Q000648:ultrastructure; D006801:Humans; D020527:Microscopy, Scanning Probe / Q000295:instrumentation*; D008872:Microwaves; D037742:Nanotubes, Carbon / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon
keywords: Carbon nanotube; Endothelial cell; Near-field scanning microwave microscopy; Soft material