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 project report tiger Active In SP Posts: 1,062 Joined: Feb 2010 21-02-2010, 01:44 PM   Memristor Presentation.ppt (Size: 320.48 KB / Downloads: 1,623) Memristor â€œ The Fourth Fundamental Circuit Element Introduction Currently known fundamental passive elements â€œ Resistors, Capacitors & Inductors. Does a 4th passive element exist.. Leon O. Chua formulated Memristor theory in his paper Memristor-The Missing Circuit Element in 1971. Memistors are passive two terminal circuit elements. Behaves like a nonlinear resistor with memory. History Of Memristor Four fundamental circuit variables- current i, voltage v, charge q, and flux linkage f Six possible combinations of these four variables Five already defined as Resistor(dv=Rdi), Capacitor(dq=Cdv), Inductor(df=Ldi), q(t)=i(T)dT, f(t)=v(T)dT The 6th relation defines memristance as df=Mdq So what is Memristance Memristance is a property of an electronic component. When charge flows in one direction, its resistance increases, and if direction is reversed, resistance decreases. When v=0, charge flow stops & component will Ëœrememberâ„¢ the last resistance it had. When the flow of charge regains, the resistance of the circuit will be the value when it was last active. Memristor Theory Two terminal device in which magnetic flux Fm between its terminals is a function of amount of electric charge q passed through the device. M(q) = dFm/dq M(q) = [dFm/dt] / [dq/dt] = V/I V(t) = M(q(t))I(t) The memristor is static if no current is applied. If I(t)=0, then V(t)=0 and M(t) is a constant. This is the essence of the memory effect. Physical analogy for a memristor Resistor is analogous to a pipe that carries water. Water(charge q), input pressure(voltage v), rate of flow of water(current i). In case of resistor, flow of water is faster if pipe is shorter and/or has a larger diameter. Memristor is analogous to a special kind of pipe that expands or shrinks when water flows through it The pipe is directive in nature. If water pressure is turned off, pipe will retain its most recent diameter, until water is turned back on. Titanium dioxide memristor On April 30, 2008, a team at HP Labs led by the scientist R. Stanley Williams announced the discovery of a switching memristor. It achieves a resistance dependent on the history of current using a chemical mechanism. The HP device is composed of a thin (5nm) Titanium dioxide film between two Pt electrodes. Initially there are two layers, one slightly depleted of Oxygen atoms, other non-depleted layer. The depleted layer has much lower resistance than the non-depleted layer. Conclusion The rich hysteretic v-i characteristics detected in many thin film devices can now be understood as memristive behaviour. This behaviour is more relevant as active region in devices shrink to nanometer thickness. It takes a lot of transistors and capacitors to do the job of a single memristor. No combination of R,L,C circuit could duplicate the memristance. So the memristor qualifies as a fundamental circuit element.
 seminar topics Active In SP Posts: 559 Joined: Mar 2010 25-03-2010, 08:53 AM MEMRISTOR ABSTRACT: We are familiar with circuit elements which are three important elements named as resistor, capacitor, and inductor. In 1971 leon chua developed a fourth fundamental element which is called MEMRISTOR. MEMRISTOR is a short for memory resistor (memory + resistor).It is a two terminal passive circuit element maintain relationship between integral current and voltage and it saves the power too .The device is based on nanoscale systems to enable coupling between solidstate electronic and ionic transport under external bias voltage. Single MEMRISTOR can perform the same logic functions as multiple transistors, making them promise way to increase computer power. A single MEMRISTOR takes atleast dozen of transistors. Implementation of MEMRISTOR can dramatically change the size and perform of existing circuits. It also reduce the booting time of pc .It can change resistance depending on amount and direction of the voltage applied and can remember its resistance even voltage is turned off. It is faster, smaller, more energy efficient alternative to flash storage. By: P.RAJITHA G.SHALINI CSE 3RD YEAR CSE 3RD YEAR ACE ENGG.COLLEGE ACE ENGG.COLLEGE Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
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 project report maker Active In SP Posts: 119 Joined: Jul 2010 16-07-2010, 10:23 PM ABSTRACT Typically electronics has been defined in terms of three fundamental elements such as resistors, capacitors and inductors. These three elements are used to define the four fundamental circuit variables which are electric current, voltage, charge and magnetic flux. Resistors are used to relate current to voltage, capacitors to relate voltage to charge, and inductors to relate current to magnetic flux, but there was no element which could relate charge to magnetic flux. This paper analyzes the fourth fundamental circuit element named ËœMemristorâ„¢ which had been proposed by a University of California, Berkeley engineer, Leon Chua in 1971, and has recently been developed by a group of researchers at Hewlettâ€œPackard led by Stanley Williams. The paper studies the implications of the discovery of this new element and highlights its potential applications in the circuit design and computer technology. To overcome this missing link, scientists came up with a new element called Memristor. These Memristor has the properties of both a memory element and a resistor (hence wisely named as Memristor). Memristor is being called as the fourth fundamental component, hence increasing the importance of its innovation. Its innovators say memrisrors are so significant that it would be mandatory to re-write the existing electronics engineering textbooks. Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
 projectsofme Active In SP Posts: 1,124 Joined: Jun 2010 15-10-2010, 12:38 PM   memristor.pptx (Size: 854.3 KB / Downloads: 218) This article is presented by: PRESENTED BY Varun Thomas S7 R MEMRISTOR INTRODUCTION A fundamental circuit A two terminal device Relates to charge and flux BASIC MEMRISTOR MODEL Doped: region of low resistance Undoped: region of high resistance R off : Resistance when w/d=0 R on: Resistance when w/d=1 TYPES OF MEMRISTOR Spintronic Memristor Titanium dioxide Memristor WORKING OF MEMRISTOR Spintronic Memristor Spin of electrons Magnetism Magneto resistance principal Electrons flow alters the magnetization state WORKING OF MEMRISTOR Titanium dioxide Memristor Two thin layer sandwich First layer oxygen deficient Oxygen vacancies control resistance
 project report helper Active In SP Posts: 2,270 Joined: Sep 2010 19-10-2010, 01:27 PM   Memristor Presentation.ppt (Size: 327.83 KB / Downloads: 213) Memristor – The Fourth Fundamental Circuit Element Presented by : Arun Kuriakose Roll No : 11 S7-EE Introduction Currently known fundamental passive elements – Resistors, Capacitors & Inductors. Does a 4th passive element exist..? Leon O. Chua formulated Memristor theory in his paper “Memristor-The Missing Circuit Element” in 1971. Memistors are passive two terminal circuit elements. Behaves like a nonlinear resistor with memory.
 seminar surveyer Active In SP Posts: 3,541 Joined: Sep 2010 24-12-2010, 02:32 PM   aREPORT.doc (Size: 1.31 MB / Downloads: 99) Introduction Memristor is a two terminal passive element which provide a similar relationship between magnetic flux and charge that a resistor gives between voltage and current. The magnetic flux Φm between the terminals is a function of the amount of electric charge q that has passed through the device. It is characterized by its memristance function describing the charge-dependent rate of change of flux with charge. Memristance is a property of an electronic component. If charge flows in one direction through a circuit, the resistance of that component of the circuit will increase, and if charge flows in the opposite direction in the circuit, the resistance will decrease. If the flow of charge is stopped by turning off the applied voltage, the component will 'remember' the last resistance that it had, and when the flow of charge starts again the resistance of the circuit will be what it was when the voltage is turned off. Memristors can be combined into devices called crossbar latches, which could replace transistors in future computers, taking up a much smaller area. They can also be fashioned into non-volatile solid-state memory, which would allow greater data density than hard drives with access times potentially similar to DRAM, replacing both components. Passive Elements Passive elements are those elements which are themselves not able to make any difference in signals applied to them. They are; 2.1 Resistor A resistor is a two-terminal electronic component that opposes an electric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm’s law: V = IR. The electrical resistance R is equal to the voltage drop V across the resistor divided by the current I through the resistor. The power dissipated by a resistor is the voltage across the resistor multiplied by the current through the resistor. 2.2Capacitor A capacitor is an electrical/electronic device that can store energy in the electric field between a pair of conductors. The process of storing energy in the capacitor is known as "charging", and involves electric charges of equal magnitude, but opposite polarity, building up on each plate. 2.3 Inductor An "ideal inductor" has inductance, but no resistance or capacitance, and does not dissipate energy. Inductance is an effect which results from the magnetic field that forms around a current-carrying conductor. Electric current through the conductor creates a magnetic flux proportional to the current. A change in this current creates a change in magnetic flux that, in turn, generates an electromotive force (EMF) that acts to oppose this change in current. Inductance is a measure of the amount of EMF generated for a unit change in current. Memristor Memristor is the fourth passive element which has created recently. It is characterized by its memristance function describing the charge-dependent rate of change of flux with charge. When the voltage to the circuit is turned off, the Memristor still remembers how much was applied before and for how long. History of Memristor We are aware of over 100 published papers going back to at least the early 1960's in which researchers observed and reported unusual 'hysteresis' in their current-voltage plots of various devices and circuits based on many different types of materials and structures. In retrospect, we can understand that those researchers were actually seeing memristance, but they were apparently not aware of it. Memristor postulated in a seminal 1971 paper in the IEEE Transactions on Circuit Theory by an Electrical Engineer Professor Leon Chua at the University of California, Berkeley. The hold-up over the last 37 years, according to professor Chua, has been a misconception that has pervaded electronic circuit theory. That misconception is that the fundamental relationship in passive circuitry is between voltage and charge. Anyone familiar with electronics knows the trinity of fundamental components: the resistor, the capacitor, and the inductor. Professor Chua predicted that there should be a fourth element: a memory resistor, or Memristor. Such a device, he figured, would provide a similar relationship between magnetic flux and charge that a resistor gives between voltage and current. In practice, it will act like a resistor whose value could vary according to the current passing through it and which would remember that value even after the current disappeared. As, Professor Leon Chua pointed out in 1971, for the sake of the logical completeness of circuit theory; a fourth passive element should in fact be added to the list. He named this hypothetical element, linking flux and charge, the ‘Memristor’. But no one knew how to build one. Building on their groundbreaking research in nanoelectronics, Stanley Williams (Senior Fellow, Information and Quantum Systems lab, HP Labs), and team are the first to prove the existence of the Memristor. They were the first to understand that the hysteresis that was being observed in the I-V curves of a wide variety of materials and structures was actually the result of memristance and something more general that can be called 'memristive behavior'. Then they went on to create an elementary circuit model that was defined by exactly the same mathematical equations as those predicted by Professor Chua for the Memristor, with the exception that this model had an upper bound to the resistance (which means that at large bias or long times, it is a memristive device). Now, 37 years later, electronics have finally gotten small enough to reveal the secrets of that fourth element within the electrical characteristics of certain nanoscale devices.
 seminar surveyer Active In SP Posts: 3,541 Joined: Sep 2010 01-01-2011, 05:09 PM   aREPORT.doc (Size: 1.31 MB / Downloads: 110) Introduction Memristor is a two terminal passive element which provide a similar relationship between magnetic flux and charge that a resistor gives between voltage and current. The magnetic flux Φm between the terminals is a function of the amount of electric charge q that has passed through the device. It is characterized by its memristance function describing the charge-dependent rate of change of flux with charge. Memristance is a property of an electronic component. If charge flows in one direction through a circuit, the resistance of that component of the circuit will increase, and if charge flows in the opposite direction in the circuit, the resistance will decrease. If the flow of charge is stopped by turning off the applied voltage, the component will 'remember' the last resistance that it had, and when the flow of charge starts again the resistance of the circuit will be what it was when the voltage is turned off. Memristors can be combined into devices called crossbar latches, which could replace transistors in future computers, taking up a much smaller area. They can also be fashioned into non-volatile solid-state memory, which would allow greater data density than hard drives with access times potentially similar to DRAM, replacing both components. Passive Elements Passive elements are those elements which are themselves not able to make any difference in signals applied to them. They are; Resistor A resistor is a two-terminal electronic component that opposes an electric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm’s law: V = IR. The electrical resistance R is equal to the voltage drop V across the resistor divided by the current I through the resistor. The power dissipated by a resistor is the voltage across the resistor multiplied by the current through the resistor. Capacitor A capacitor is an electrical/electronic device that can store energy in the electric field between a pair of conductors. The process of storing energy in the capacitor is known as "charging", and involves electric charges of equal magnitude, but opposite polarity, building up on each plate. When a capacitor is connected to a current source, charge is transferred between its plates at a rate: i (t) = dq (t) / dt. Inductor An "ideal inductor" has inductance, but no resistance or capacitance, and does not dissipate energy. Inductance is an effect which results from the magnetic field that forms around a current-carrying conductor. Electric current through the conductor creates a magnetic flux proportional to the current. A change in this current creates a change in magnetic flux that, in turn, generates an electromotive force (EMF) that acts to oppose this change in current. Inductance is a measure of the amount of EMF generated for a unit change in current. For an inductor v (t) =L di/dt There are four fundamental circuit variables: electric current, voltage, charge, and magnetic flux. For these variables, we have resistors to relate current to voltage, capacitors to relate voltage to charge, and inductors to relate current to magnetic flux, but we were missing one to relate charge to magnetic flux. That is where the Memristor comes in. Memristor Memristor is the fourth passive element which has created recently. It is characterized by its memristance function describing the charge-dependent rate of change of flux with charge. When the voltage to the circuit is turned off, the Memristor still remembers how much was applied before and for how long. M (q) = dΦm/dq History of Memristor We are aware of over 100 published papers going back to at least the early 1960's in which researchers observed and reported unusual 'hysteresis' in their current-voltage plots of various devices and circuits based on many different types of materials and structures. In retrospect, we can understand that those researchers were actually seeing memristance, but they were apparently not aware of it. Memristor postulated in a seminal 1971 paper in the IEEE Transactions on Circuit Theory by an Electrical Engineer Professor Leon Chua at the University of California, Berkeley. The hold-up over the last 37 years, according to professor Chua, has been a misconception that has pervaded electronic circuit theory. That misconception is that the fundamental relationship in passive circuitry is between voltage and charge. Anyone familiar with electronics knows the trinity of fundamental components: the resistor, the capacitor, and the inductor. Professor Chua predicted that there should be a fourth element: a memory resistor, or Memristor. Such a device, he figured, would provide a similar relationship between magnetic flux and charge that a resistor gives between voltage and current. In practice, it will act like a resistor whose value could vary according to the current passing through it and which would remember that value even after the current disappeared. As, Professor Leon Chua pointed out in 1971, for the sake of the logical completeness of circuit theory; a fourth passive element should in fact be added to the list. He named this hypothetical element, linking flux and charge, the ‘Memristor’. But no one knew how to build one. Building on their groundbreaking research in nanoelectronics, Stanley Williams (Senior Fellow, Information and Quantum Systems lab, HP Labs), and team are the first to prove the existence of the Memristor. They were the first to understand that the hysteresis that was being observed in the I-V curves of a wide variety of materials and structures was actually the result of memristance and something more general that can be called 'memristive behavior'. Then they went on to create an elementary circuit model that was defined by exactly the same mathematical equations as those predicted by Professor Chua for the Memristor, with the exception that this model had an upper bound to the resistance (which means that at large bias or long times, it is a memristive device). Now, 37 years later, electronics have finally gotten small enough to reveal the secrets of that fourth element within the electrical characteristics of certain nanoscale devices. Evolution Many researchers observed and reported unusual 'hysteresis' in their current-voltage plots of various devices and circuits based on many different types of materials and structures. They were actually seeing memristance, but apparently not aware of it. All electronic textbooks have been teaching using the wrong variables - voltage and charge - explaining away inaccuracies as anomalies. What they should have been teaching is the relationship between changes in voltage, or flux, and charge. Without Professor Chua's circuit equations, making use of this device is not possible. It's such a funky thing. People were using all the wrong circuit equations. The fact that the magnetic field does not play an explicit role in the mechanism of memristance is one possible reason why the phenomenon has been hidden for so long. Those interested in memristive devices were searching in the wrong places. The mathematics simply require there to be a nonlinear relationship between the integrals of the current and voltage. Another significant issue that was not anticipated by Chua is that the state variable w, which in this case specifies the distribution of dopants in the device, is bounded between zero and D. The state variable is proportional to the charge q that passes through the device until its value approaches D; this is the condition of ‘hard’ switching (large voltage excursions or long times under bias). As long as the system remains in the Memristor regime, any symmetrical alternating-current voltage bias results in double-loop i–v hysteresis that collapses to a straight line for high frequencies (Fig. 2b). Multiple continuous states will also be obtained if there is any sort of asymmetry in the applied bias (Fig. 2c). The proof of its existence remained elusive - in part because memristance is much more noticeable in nanoscale devices. The crucial issue for memristance is that the device's atoms need to change location when voltage is applied, and that happens much more easily at the nanoscale.
 kailas reddy Active In SP Posts: 1 Joined: Feb 2011 27-02-2011, 04:40 PM SIR, I WANT MORE INFO.. ABOUT MEMRISTOR WOULD U SEND THAT TO ME... THAT SHOULDEXCEPT THE MATTER PRESENT IN THIS SITE
 seminar project explorer Active In SP Posts: 231 Joined: Feb 2011 15-03-2011, 08:58 AM Memristor P.Balamurali Krishna & Rajesh.R Department of Electronics and Communication Engineering M.G. College of Engineering   Memristor.pdf (Size: 248.1 KB / Downloads: 149) Abstract A memristor is a passive two-terminal circuit element in which the resistance is a function of the history of the current through and voltage across the device. Memristor theory was formulated and named by Leon Chua in a 1971 paper. Chua strongly believed that a fourth device existed to provide conceptual symmetry with the resistor, inductor, and capacitor. This symmetry follows from the description of basic passive circuit elements as defined by a relation between two of the four fundamental circuit variables. A device linking charge and flux (themselves defined as time integrals of current and voltage), which would be the memristor, was still hypothetical at the time. However, it would not be until thirty-seven years later, on April 30, 2008, that a team at HP Labs led by the scientist R. Stanley Williams would announce the discovery of a switching memristor. Based on a thin film of titanium dioxide, it has been presented as an approximately ideal device. Introduction A memristor is a passive two-terminal electronic component for which the resistance (dV/dI) depends in some way on the amount of charge that has flowed through the circuit. When current flows in one direction through the device, the resistance increases; and when current flows in the opposite direction, the resistance decreases, although it must remain positive. When the current is stopped, the component retains the last resistance that it had, and when the flow of charge starts again, the resistance of the circuit will be what it was when it was last active. [8] More generally, a memristor is a two-terminal component in which the resistance depends on the integral of the input applied to the terminals (rather than on the instantaneous value of the input as in a varistor). Since the element "remembers" the amount of current that has passed through it in the past, it was tagged by Chua with the name "memristor." Another way of describing a memristor is that it is any passive two-terminal circuit elements that maintains a functional relationship between the time integral of current (called charge) and the time integral of voltage (often called flux, as it is related to magnetic flux). The slope of this function is called the memristance M and is similar to variable resistance. Batteries can be considered to have memristance, but they are not passive devices. The definition of the memristor is based solely on the fundamental circuit variables of current and voltage and their time-integrals, just like the resistor, capacitor, and inductor Need For Memristor Memristance (Memory + Resistance) is a property of an Electrical Component that describes the variation in Resistance of a component with the flow of charge. Any two terminal electrical component that exhibits Memristance is known as a Memristor. Memristance is becoming more relevant and necessary as we approach smaller circuits, and at some point when we scale into nano electronics, we would have to take memristance into account in our circuit models to simulate and design electronic circuits properly. An ideal memristor is a passive two-terminal electronic device that is built to express only the property of memristance (just as a resistor expresses resistance and an inductor expresses inductance). However, in practice it may be difficult to build a 'pure memristor,' since a real device may also have a small amount of some other property, such as capacitance (just as any real inductor also has resistance).A common analogy for a resistor is a pipe that carries water. The water itself is analogous to electrical charge, the pressure at the input of the pipe is similar to voltage, and the rate of flow of the water through the pipe is like electrical current. Just as with an electrical resistor, the flow of water through the pipe is faster if the pipe is shorter and/or it has a larger diameter. An analogy for a memristor is an interesting kind of pipe that expands or shrinks when water flows through it. If water flows through the pipe in one direction, the diameter of the pipe increases, thus enabling the water to flow faster. If water flows through the pipe in the opposite direction, the diameter of the pipe decreases, thus slowing down the flow of water. If the water pressure is turned off, the pipe will retain it most recent diameter until the water is turned back on. Thus, the pipe does not store water like a bucket (or a capacitor) – it remembers how much water flowed through it. Possible applications of a Memristor include Nonvolatile Random Access Memory (NVRAM), a device that can retain memory information even after being switched off, unlike conventional DRAM which erases itself when it is switched off. Another interesting application is analog computation where a memristor will be able to deal with analog values of data and not just binary 1s and 0s. Memristor Theory And Its Properties: Definition of Memristor “The memristor is formally defined as a two-terminal element in which the magnetic flux Φm between the terminals is a function of the amount of electric charge q that has passed through the device.” Figure 5. Symbol of Memristor. Chua defined the element as a resistor whose resistance level was based on the amount of charge that had passed through the memristor Memristance Memristance is a property of an electronic component to retain its resistance level even after power had been shut down or lets it remember (or recall) the last resistance it had before being shut off. Conclusion By redesigning certain types of circuits to include memristors, it is possible to obtain the same function with fewer components, making the circuit itself less expensive and significantly decreasing its power consumption. In fact, it can be hoped to combine memristors with traditional circuit-design elements to produce a device that does computation. The Hewlett-Packard (HP) group is looking at developing a memristor-based nonvolatile memory that could be 1000 times faster than magnetic disks and use much less power.
 seminar class Active In SP Posts: 5,361 Joined: Feb 2011 11-04-2011, 04:37 PM   sunder seminar.docx (Size: 87.76 KB / Downloads: 61) MEMRISTOR An array of 17 purpose-built oxygen-depleted titanium dioxide memristors built at HP Labs, imaged by an atomic force microscope. The wires are about 50 nm, or 150 atoms, wide. Electric current through the memristors shifts the oxygen vacancies, causing a gradual and persistent change in electrical resistance. Memristor (pronounced "memory resistor") is a name of passive two-terminal circuit elements in which the resistance is a function of the history of the current through and voltage across the device and is expressable in terms of a functional relationship between charge and magnetic flux linkage. Memristor theory was formulated and named by Leon Chua in a 1971 paper. On April 30, 2008, a team at HP Labs announced the development of a switching memristor based on a thin film of titanium dioxide[It has a regime of operation with an approximately linear charge-resistance relationship as long as the time-integral of the current stays within certain bounds. These devices are being developed for application in nanoelectronic memories, computer logic, and neuromorphic computer architectures. 2. BACKGROUND A memristor is a passive two-terminal electronic component whose present resistance depends in some way on the amount of charge that has flowed through the circuit. When current flows in one direction through the device, the resistance increases; and when current flows in the opposite direction, the resistance decreases, although it must remain positive. When the current is stopped, the component retains the last resistance that it had, and when the flow of charge starts again, the resistance of the circuit will be what it was when it was last active. More generally, a memristor is a two-terminal component in which the resistance depends on the integral of the input applied to the terminals (rather than on the instantaneous value of the input as in a varistor). Since the element "remembers" the amount of current that has passed through it in the past, it was tagged by Chua with the name "memristor." Another way of describing a memristor is that it is any passive two-terminal circuit elements that maintains a functional relationship between the time integral of current (called charge) and the time integral of voltage (often called flux, as it is related to magnetic flux). The slope of this function is called the memristance M and is similar to variable resistance. Batteries can be considered to have memristance, but they are not passive devices. The definition of the memristor is based solely on the fundamental circuit variables of current and voltage and their time-integrals, just like the resistor, capacitor, and inductor. Unlike those three elements however, which are allowed in linear time-invariant or LTI system theory, memristors of interest have a nonlinear function and may be described by any of a variety of functions of net charge. There is no such thing as a standard memristor. Instead, each device implements a particular function, wherein the integral of voltage determines the integral of current, and vice versa. A linear time-invariant memristor is simply a conventional resistor. In his 1971 paper, memristor theory was formulated and named by Leon Chua, extrapolating the conceptual symmetry between the resistor, inductor, and capacitor, and inferring the memristor was a similarly fundamental device. (However, as mentioned above, if it has no non-linearity then it is the same as a standard resistor. It is more meaningful to compare it with a varistor, which has a non-linear relationship between current and voltage.) Other scientists had already proposed fixed nonlinear flux-charge relationships, but Chua's theory introduced generality. Like other two-terminal components (e.g., resistor, capacitor, inductor), real-world devices are never purely memristors ("ideal memristor"), but will also exhibit some amount of capacitance, resistance, and inductance. Note however that a "memristor" with constant M and a resistor with constant R (i.e. not a varistor) are the same thing. 3. THEORY The memristor is essentially a two-terminal variable resistor, with resistance dependent upon the amount of charge q that has passed between the terminals. To relate the memristor to the resistor, capacitor, and inductor, it is helpful to isolate the term M(q), which characterizes the device, and write it as a differential equation.
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