nanoelectronic devices with the effect of resistive switching, which consists in a reversible change of resistance in response to electrical stimulation [5] and is identified with the memristive effect. [6] Despite the significant progress in understanding of the memristive effect and approaching maturity of the technology of resistiveswitching devices over the last 10 years, there are still a number of fundamental problems to solve.A key problem on the way of using resistive-switching devices as programmable elements in memory devices and mixed analog-digital processors of new generation is the variability of resistive switching parameters inherent to memristive thin-film devices. [7] Achieving stable switching between the nonlinear resistive states is also an important task on the way to implementing large passive crossbar arrays of memristors and solving the problem of leakage currents in them. [8,9] Metal-oxide memristive devices are most compatible with the traditional complementary metal oxide semiconductor (CMOS) process and exhibit a valence change memory effect. [10] The variation of switching parameters in such devices is caused by the stochastic nature of migration of oxygen ions and/or vacancies responsible for the local oxidation and recovery of conductive channels (filaments) and is accompanied by the degradation of switching parameters in the case of uncontrolled oxygen exchange between the dielectric and electrode materials.The traditional approaches to control the reproducibility of resistive switching include the formation of special electric field concentrators [11][12][13] and appropriate selection of materials/interfaces in memristive device structure. In the latter case, bilayer or multilayer structures are formed, in which the switching oxide alternates with a barrier/buffer layer (layers) to control the migration of oxygen vacancies, [14,15] with a layer of low dielectric constant [16,17] to obtain nonlinear currentvoltage (I-V) characteristics, or with a layer of higher/lower thermal conductivity [18,19] for the removal/retention of heat in the switching area and to achieve analog switching character. To tune the resistive states with given accuracy, regardless of

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We provide direct experimental comparison of the optoacoustic imaging performance of two different 64-element linear detector array (LDA) units based on polyvinylidene difluoride (PVDF) films. The first LDA unit was based on traditional flexible circuit (FC) technology and consisted of an FC glued to the nonmetalized signal surface of a 28-μm-thick PVDF film providing 300  /  80-μm axial resolution/lateral resolution (AR/LR) and 0.4-kPa noise equivalent pressure of its single element. The other LDA unit was manufactured using a technology of low-temperature photolithographic etching (PE) of a signal electrode onto a 25-μm-thick PVDF film providing 300  /  40-μm AR/LR and 1 kPa noise equivalent pressure. As compared with a previously reported LDA unit based on a 100-μm PVDF thick film, the main advantage of using the thinner PVDF films was 10-fold improvement in axial resolution, whereas the main drawback was 10-fold increased noise equivalent pressure. In terms of in vivo imaging performance, higher bandwidth of PE LDA probe was more important than the higher sensitivity of FC LDA unit.

It is shown that two modes of resistive switching – bipolar and volatile unipolar – are peculiar for the Ag/Ge/Si structures with germinating dislocations in the germanium layer. In this modes the structures have stable states of electric current with ION/IOFF ~1.5–2.7. The volatile unipolar type of switching can be caused by the capture of charge carriers to deep levels associated with lattice defects in the Ge film of the memristor. At the same time, bipolar switching is associated with the drift of Ag+ ions along germinating dislocations.