1. Welcome
Seminar on
MEMRISTOR
24 Aug. 2012

2. MEMRISTOR
Memristor
Memory + Resistor
Memristor

3. Analogy Of Memristor
 The diameter of pipe
remains same when the
current is switched off,
until it is switched on
again.
 The pipe, when the
current is switched on
again, remembers what
current has flowed
A RESISTOR WITH MEMORY
through it. BEHAVES LIKE A PIPE

4. Definition of Memristor
 A memristor is a device whose resistance
varies as a function of flux and current. This
allows it to “remember” what has passed
through the circuit.
 Characterized by Memristance

5. What Is It?
 A type of electrical
circuit.
 The fourth mystery
element that joins
the capacitor,
resistor, and
inductor.

6. Memristance
 Memristance is simply charge-dependent
resistance.
V(t) = M(q(t))*I(t)
Unit - ohm (Ω)
Symbol

7. Emergence Of Memristic Theory
 Theory was developed in 1971 by
Professor Leon Chua at University of
California, Berkeley.
 Found while exploring symmetry
between the three fundamental passive
linear circuit elements
 In 2006, R.Stanley Williams
developed practical model.

8. Symmetry Of Relationships
Voltage Current
(V) (i)
Charge Flux (Φ)
(q)

9. Symmetry Of Relationships
Voltage Current
(V) (i)
Capacitors q=Cv
Charge Flux (Φ)
(q)

10. Symmetry Of Relationships
Voltage Resistors Current
(V) v=Ri (i)
Capacitors q=Cv
Charge Flux (Φ)
(q)

11. Symmetry Of Relationships
Voltage Resistors Current
(V) v=Ri (i)
v=dΦ/dt i=dq/dt
Capacitors q=Cv Φ = Li Inductors
Charge ? Flux (Φ)
(q) ?

12. Symmetry Of Relationships
Voltage Resistors Current
(V) v=Ri (i)
v=dΦ/dt i=dq/dt
Capacitors q=Cv Φ = Li Inductors
Charge Φ=Mq
Flux (Φ)
(q) Memristors

13. Relationship With Other Variables
Φ = M q
dΦ/dt = M(q) dq/dt
V(t) = M(q) I
P = I² M(q)

14. Memristic State
 Found when researching ways to overcome
nano-scale manufacturing issues.
 Memristivity has an inverse square relationship
with thickness of the material, so
smaller = better!
 Nonvolatile state can be accomplished by
memristors because their state is encoded by
impedance (physically), not by voltage.

15. WORKING
2 nm PT TiOv(2-x) PT
(-)ve TiO2 (+)ve
3 nm
Reduced
Oxidized
 Applied voltage makes the oxygen vacancies
(+ve) to shift towards the –ve voltage.

16. Benefits Of Memristor Technology
 Would allow for a quicker boot up since
information is not lost when the device is
turned off.
 Hard Disk + RAM = MEMRISTOR
 Uses less energy and produces less heat.
 Creating a Analog Computer that works
much faster than Digital ones

17. Benefits Of Memristor Technology
 Provides greater resiliency and reliability
when power is interrupted in data centers.
 Density allows for more information to
be stored.

18. What Sets Memristor Apart ??
 Conventional devices use only 0 and 1;
Memristor can use anything between 0 and
1.
 Faster than Flash memory.
 Allow digital cameras to take pictures with
no delay inbetween
 Innovating nanotechnology due to the fact
that it performs better the smaller it
becomes.

19. What Sets Memristor Apart ??
 By changing the speed and strength of the
current, it is possible to change the behavior of
the device.
 A fast and hard current causes it to act as a
digital device.
 A soft and slow current causes it to act as an
analog device.

20. Future Technological Significance
 Hope to one day have
a computer that
processes information
in the same way as the
human brain.
 Gaining control
over the device
could lead to
computers that
actually learn.

21. Future Technological Significance
Being implemented to do neural
computing. (post office, banks).
Pattern recognition and learning.
Crossbar latches to replace
transistors.
New forms signal processing and
control systems.

22. Not Perfect Yet !
 Though hundreds of thousands of
memristor semiconductors have already
been built, there is still much more to be
perfected.
 Needs more defect engineering.
 No design standards (rules).