The ripples shown in Figure 5a,c were caused by laser diffraction on the insulating Si3N4 cantilever (for more details, see Additional file 1). Figure 5 Experimental results vs. Ansoft Maxwell simulation. (a, c) The F ele(+25 V) and F ele(−25 V) distribution along the X-axis (0.25-μm spacing from 10 to 15 μm) and the Z-axis. (b, d) The results of Ansoft Maxwell simulation of electrostatic field

distribution under V app = +25 and −25 V, respectively. In the future, the pyramidal shape of the Si3N4 tip could be modified using a focused ion beam system to create a cylindrical shape in order to avoid the possibility of experimental Luminespib fluctuations resulting from the shape of the tip. This probe could be employed to scan surface topographies by mapping f-d curves, and the interaction force between the charged Teflon particle and sample would give a direct indication of the local electric field and properties of the sample. Conclusions In summary,

10058-F4 order this paper reported the direct measurement of the electrostatic field beside a parallel plate condenser using a charged sTNP on an AFM tip. Experimental results were then compared with those obtained through simulation. A sTNP tip was fabricated by attaching a single 210-nm Teflon nanoparticle at the vertex of a Si3N4 AFM tip and was charged via contact electrification. The lateral/vertical resolution of the electrostatic force measurement is 250/100 nm, respectively. The minimum F ele that can be measured using this method is less than 50 pN. This technique provides a novel means of studying the electric properties of electrical devices. The AFM tip is able to hold a single charged nanoparticle, making it possible to directly quantify the local electric/magnetic field, charge distribution, and electrostatic force of a sample surface

using an AFM system. The charged Rucaparib in vivo sTNP tip could find a wide application in electrical research at the nanoscale. Authors’ information JMC received his M.S. degree in engineering and system science from National Tsing Hua University, Hsinchu, Taiwan in 2005. He is currently working towards finishing his Ph.D. at the Institute of NanoEngineering and Microsystems, National Tsing Hua University, Hsinchu, Taiwan. WYC is currently working towards finishing a Ph.D. degree at the Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan. FRC is a professor at the Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan. FGT is a professor at the Department of Engineering and System Science, National TsingHua University, Hsinchu, Taiwan. He received his Ph.D. degree in mechanical engineering from the University of California, Los Angeles (UCLA), under the supervision of Prof.