Memristor, working, functions

1. Sharad Institute of Technology College of Engineering,
Yadrav (Ichalkaranji)
Presented by,
Ms. Chetan D. Patil
Department of Electrical Engineering
A presentation on
Memristors
(A memristic theory of passive electrical component)

2. Contents:
• History
• Memristor and its electronic symbol
• Theory and Analogy
• Construction and Working
• Memristance
• Symmery of relationships
• Benefits and Limitations
• Applications
• Memrister patents
• Future technologies
• References
• Conclusion

3. History:
• In 1971 by Professor Leon Chua
University of California, Berkeley
• In 2008, a team at HP Labs under R. Stanley Williams

4. Memrister:
• Semiconductor device
• Regulates flow of electrical current
• Resistance varies as a function of flux and charge
• Switch used to connect multiple inputs and outputs in a matrix
• Remembers the amount of charge that has previously flowed through it
Symbol:

5. Theory:
• Functional relationship between magnetic flux linkage Φm(t) and the amount of electric charge
that has flowed
f(Φm (t), q(t)) = 0
Why so late?
• Effect of Atomic-scale movement
• Pop-up on Nano scale of William’s devices

6. Analogy:
• Resistor = water pipe
• Water = electric charge
• Pressure = voltage
• Flow of water = electric current
• Small diameter = fast water flow
• Large diameter = Slow water flow
• Memrister expands or shrinks
Ref: google/memristorbjbz

7. Construction:
• 2 Platinum electrodes
• Silicon dioxide and Titanium dioxide
• Resistance dependency on polarity,
magnitude and length
• Array of 17 purpose-built oxygen-
depleted titanium dioxide
• Imaged by an atomic force microscope
• Wires are about 50 nm (or 150 atoms)
wide
Ref: google/memristorbjbz

8. Working:
• When voltage is applied
• Movement of Oxygen atoms
• Thinner and thicker material layer
• Resistance change
• When voltage turned off
• Remembers memory

9. Memristance:
• Property of memrister
• Unit is Ohm
• Resistance increases when charge flows in one direction
• Resistance decreases when charge flows in opposite direction
• Charge is stopped then it remembers the last resistance that it had

10. Symmetry of relationships:
• Found while exploring symmetry between three fundamental passive linear circuit elements
Voltage (V)
Flux (Ø)
Charge (q)
Current (I)
Resistors
(v=Ri)
Capacitors
(q=Cv)
Inductors
(Ø=Li)
Memristors
(Ø=Mq)
v= dØ/dt i= dq/dt
Ref: google/memristorbjbz

11. Fundamental passive linear elements:
Ref: google/memristorbjbz

12. Benefits:
• Unique properties of resistor, inductor, capacitor
• Capable of replacing D-RAM and hard drives
• Retain memory without power
• Less heat generation
• Device storage of 100 gigabytes in a square centimeter
• Quicker boot-up
• Requires less voltage
• Less power requirement
• Greater resiliency
• Good reliability
• Energy-efficient memory chips

13. Limitations:
• Commercially not available
• Can give wrong patterns at the beginning
• Less speed about 1/10th of D-RAM

14. Applications:
• Non-volatile memory :
• Retain memory states, and data, in power-off modes
• Low-power and remote sensing applications:
• Memcapacitors and meminductors allows storage of charge
• Nano-scale low power memory
• Distributed state storage

15. Memristor patents:
• Programmable Logic
• Neural Networks
• Reconfigurable Computing
• Brain-computer Interfaces
• 3nm Memristors in fabrication

16. Future technological significance:
• Pattern recognition
• Crossbar latches instead transistors
• Signal processing
• Control systems
• Used to do digital logic instead NAND

17. References:
• http://spectrum.ieee.org/semiconductors/processors/how-we-found-the-missing-memristor
• http://innovativeblood.blogspot.in/2011/02/memristor-missing-circuit-element.html
• http://whatis.techtarget.com/definition/memristor
• http://www.memristor.org/reference/research/13/what-are-memristors
• http://www.channelregister.co.uk/2011/12/27/memristors_and_mouttet/
• http://thefutureofthings.com/4060-flexible-memristor-chips/
• http://www.vrg.utoronto.ca/~shortena/documents/memristor.pdf

18. Conclusion:
We can use the memrister as a semiconductor device which regulates
flow of electrical current through it and operates even after power cut-off. Its resistance
varies as a function of flux and charge. It remembers the amount of charge that has
previously flowed through it and this data can be used for next operation.

19. Thank you ….