The document discusses memristors, which were proposed in 1971 as a fourth fundamental circuit element along with resistors, capacitors, and inductors. It provides background on memristors, including how they were first theorized and then created experimentally in 2008. Memristors can "remember" the amount of charge that has previously flowed through the device. The document discusses potential applications of memristors in areas like neural networks, due to their similarity to biological synapses. It concludes that memristors may enable new technologies but their advantages over other memory technologies still need to be fully evaluated.

1. THE MISSING FUNDAMENTAL
ELEMENT
Memristor
PRESENTED BY –
 SAURAV ROY

2. 3 FUNDAMENTAL PASSIVE CIRCUIT ELEMENTS
Inductor, L (H)
Capacitor, C (F) Resistor, R (Ω)

3. SYMMETRY OF RELATIONSHIPS
Voltage
(V)
Current(i)
Charge
(q)
Flux (Φ)
dΦ = Ldi Inductors
?
?
v=dΦ/dt i=dq/dt
Resistors
dv=Rdi
dq=CdvCapacitors

4. FOUNDER OF MISSING
ELEMENT
Leon Chua proposed the existence of
memristor in 1971.

5. 𝑣 = 𝑅 𝑥, 𝑖 𝑖
𝑑𝑥
𝑑𝑡 = 𝑓(𝑥, 𝑖)
o For all passive memristors the generalized forms are
defined as follows
Where x= (x1,x2,x3….xn)denotes n state variables x1,x2,x3…..xn which
do not depend on any external voltage or current.

6. SYMMETRY OF RELATIONSHIPS
Memristors
dΦ=Mdq
Voltage
(V)
Current
(i)
Charge
(q) Flux (Φ)
dΦ = Ldi
Inductorsv=dΦ/dt
i=dq/dt
Resistors
dv=Rdi
dq=Cdv
Capacitors

7.  Any two terminal devices which exhibits a pinched
hysteresis loop in the V-I plane when driven by any
bipolar periodic voltage or current waveform, for
any initial conditions, is a memristor.
 It depends on the frequency.
 The area enclosed within the part of the pinched hysteresis loop in the first quadrant,
and the third quadrant, of the vi plane shrinks continuously as the frequency ꙍ
increases, and the hysteresis loop tends to a straight line through the origin as ꙍ tends
to ∞.

8.  A memristor is a semiconductor whose resistance
varies as a function of flux and charge. This allows it
to “remember” what has passed through the circuit.
 Memristor is a hypothetical non-linear passive two
terminal electrical component relating electric
charge and magnetic flux linkage.
MEMRISTOR
MEMORY RESISTOR+
Memristor

9.  In 2008 a team lead by Stanley
Williams created the first
memristor.
 As its effect depends on atomic-scale movements, it
only poped up on the nanoscale of William’s
devices.
For RON<<ROFF the memristance was to be determined
as follows
 This is the curve that observed by HP which is similar
to the prescribed curve of Leon. O Chua.

10. WORKING PRINCIPLE
o Applied voltage makes the oxygen vacancies (+ve) to shift towards the –ve voltage.
• TiO2-x region doped with oxygen vacancies
• In the TiO2-x region, the ratio between titanium atoms and oxygen atoms has been altered such that
there is less oxygen than in a regular TiO2 sample
• The resistance of the device when w = D will be designated RON and when w = 0 the resistance will
be designated as ROFF .
PT PTTiO(2-x)
TiO2
3 nm
2 nm
OxidizedReduced
(-)ve (+)ve
D
W

11. o In the year 1952, Hodgkin & Huxley had erroneously named two circuit elements associated
with the Potassium ion and the Sodium ion as time-varying conductance in there model.
o Leon Chua et al. 2012 solved many hitherto unsolved paradox associated with the Hodgkin-
Huxley time varying potassium conductance is in fact a first order memristor and the
Hodgkin-Huxley time varying Sodium conductance is in fact a second order memristor.
Memristive synapses are obviously becoming reality, but their real competitive advantage
against mainstream technologies (such as CMOS-based floating-gate memories) has yet to
be evaluated .

12. A memristor has a memory and at the same time is also
able to change data encoded by its resistance state. In
this sense, a memristor is similar to a synapse,
 The Human Brain possesses nearly 10 billion
neurons,each of which has direct synaptic connections to
nearly 10,000 neurons.A connection between two
neurons in the brain with a high level of plasticity that is
able to modify the efficiency of signal transmission
between neurons under the influence of the transmission
itself. A memristor enables scientists to build a true
neural network,and the physical properties of
memristors mean that a minimum, they can be made as
small as conventional chips.
Synapse

14. CONCLUSIO
NoThe other applications of memristors are as follows:
• As Image Processor
• As pattern Recognizer
• Can perform logic operations
• In artificial neural networks
• Can work as both memory and logic functions
• Higher data density due to nano-scale size
• Compatible with CMOS process and provide innovating
nanotechnology due to the fact that it performs better the

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