ИСТИНА

A system of nanoelctrodes is one of the main components of molecular transistors, biosensors [1] and many other nanodevices. Creating a few nanometer gap between two electrodes is a very difficult task. There are several methodes, including breakup of thin films [2], deposition of additional metal layers in a gap prepared via conventional lithography [3] and electromigration [4]. We use the electromigration effect, which increases the mobility and movement of metal atoms when a current of high density is applied to a sample, to design a planar system of nanoelectrodes. Our method is based on preparing a thin and narrow metallic nanowire via conventional electron-beam lithography and metal evaporation. A high density current is sent through the nanowire following a certain algorithm. The nanowire’s conductivity drops over time, due to a localized reduction in its cross-section, and this continues until the conductivity reaches a critical value. Some time later, the nanowire spontaneously breaks up as a result of the relaxation of its structure, leading to the formation of a nanometer sized gap. Polymer-protected nanoelectrodes exhibit substantial ionic-current reduction in near-physiological conditions and enable direct DNA detection in aqueous solution as shown in [5]. References [1] Parshintsev, A. A., Soldatov E.S., et al. (2014). Bulletin of the Russian Academy of Sciences: Physics 78(2): 144-148. [2] Böhler, T., Grebing, J., MayerGindner, A., et al.,Nanotecnology, 2004, vol. 15, p. 465. [3] Sapkov, I. and Soldatov, E.S., Proc. SPIE Int. Conf. Micro and NanoElectronics, 2012, vol. 8700. [4] Heersche, H.B., Lientschnig, G., O’Neill, K., et al., Appl. Phys. Lett., 2007, vol. 91, p. 072107. [5] Zhang, H., et al. (2009). Small 5(24): 2797-2801.