Simulation based comparison between a transversal and a tangential memristor model with a capacitance in parallel

Abstract

In non-linear measurements, the applied stimulus itself affects the electrical properties of the underlying tissue. If corresponding voltage-current plots exhibit pinched hysteresis loops with pinched point in the origin of coordinates, the tissue can be classified as a memristor. Several organic memristors like human skin, venus flytrap and slime mould memristors have been demonstrated. However, measurements on organic memristors are usually affected by parasitic elements like a capacitance which will influence the appearance of the recorded pinched hysteresis loops. Here we study the parallel connection of two different memristor types, one with tangential and the other with transversal pinched hysteresis loop, and a capacitance by simulations. The simulations are inspired by human skin; beside the sweat ducts that can be modelled as a transversal memristor, the surrounding tissue, the stratum corneum exhibits non-linear electrical properties, as well. Based on a systematic study we suggested that the stratum corneum may be modelled as a tangential memristor. We demonstrate here by simulations that hysteresis loops with two pinched points can be achieved if a tangential memristor model is connected in parallel to a capacitance. Similar results were obtained from the skin recordings of some subjects; examples are presented here. Furthermore, if both the tangential and the transversal memristor models contribute to the simulation, quite asymmetric pinched hysteresis loops are obtained which are similar to recordings of some other test subjects.

Questioning the aloe vera plant and apple memristors

“…2 , 3 , S1 , and S2 ). Shifts of the pinched point away from the origin of coordinates or two pinched points can be explained by a capacitor in parallel with the underlying memristors [ 9 ].…”

The non-linear electrical properties of silver/silver chloride electrodes in sodium chloride solution

“…Pinched hysteresis loops have been shown for the silver/silver chloride electrodes in sodium chloride for different voltage stimuli and it is possible to classify the overall setup as a memristor. Shifts in pinched point position away from the origin of coordinates can be explained by parasitic capacitance and DC offsets [ 14 ].…”

“…2e and 2f and [ 4 ]). For the sweat duct memristor in human skin, the two branches of the hysteresis loop cross the pinched point with different slopes (transversal memristor, see [ 14 ]). The orientation of the pinched hysteresis loop was always counter-clockwise in the first quadrant and clockwise in the third for the sweat duct memristor (see [ 4 ]).…”

All Pinched Hysteresis Loops Generated by (α, β) Elements: in What Coordinates They May be Observable

“…On the other hand, the ω 2 criterion enables evaluating the area, but only for harmonic driving signals. The cause of the asymmetry of the PHL can be seen in that the corresponding system cannot be properly modeled only by one ideal (α,β) element but via a more complex scheme of interconnected models, which in their entirety exhibit a more complicated behavior [27], [44]. As one more reason of the asymmetry, the model of some systems cannot be compounded from a mere set of two-terminal (α,β) elements [3].…”