Solution-Processed Flexible Memory Devices Dr. Nadine Gergel-Hackett Dr. Behrang Hamadani Dr. Curt Richter Dr. David Gundlach
Mar 31, 2015
Solution-Processed Flexible Memory Devices
Dr. Nadine Gergel-HackettDr. Behrang Hamadani
Dr. Curt RichterDr. David Gundlach
Technology
MotivationFlexible electronics is an emerging industry that “sprays” electronic devices onto inexpensive plastic sheets(like inkjet printer on an overhead transparency)
Problem: Currently no method exists in flexible electronics for fabricating non-volatile low operation voltage memory devices ie devices that “hold” written state without an applied voltage
Completed design and fabrication of electronic memory devices on inexpensive plastic substrates
actual devices
Commercial Applications
Integrated Sensor is Structure – T. Clark/DARPA
sensor pack
power supplyprocessor &RFID communication
Memory indisplay
Sensor Tape – J. Ricklin/DARPA
Flexible memory devices would have applications in almost all flexible electronics circuits, some possible uses of flexible electronics include:
Advantages of Method of Device Fabrication:
• Can be performed at room temperature and pressure
• Simplified design
• Inexpensive fabrication procedures
Technology - Combining separate existing technologies
(a)Contact
Contact
Flexible Substrate
Sol gel
TiO2
actual devices
Technology•Devices showed an electrical switching with memory behavior
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6-4x10-4
-2x10-4
0
2x10-4
4x10-4
Cur
rent
(A
)
Voltage (V)
Electrical characteristics of device
Technology Applications
Areas for Improvement:
“write” and “erase” voltage values, and on/off ratios vary between devices, and increase with operation
Devices switched maximum of <10 times before permanently remaining in high state
Source of electrical switching behavior not yet well studied
-4 -2 0 2 4
-5.0x10-3
0.0
5.0x10-3
1.0x10-2
Cur
rent
(A
)
Voltage (V)
1
2
3
4
5
6
Technology Applications
0 20 40 60 80
-28.0
-24.5
-21.0
-17.5
-14.0
-10.5
-7.0
-3.5
0.0
3.5
7.0
logic
"0" logic "0"
Vol
tage
App
lied
(V)
Time (s)
logic "1"
readreadread
write
erase
Cur
rent
(A
)
0.02
0.01
0.00
-0.01
Potential Applications :The Missing Piece for the Realization of Flexible Electronics
DisplaySensors
Logic
(computing)
Memory (Low
Power,
Re-Write
able)
“Solution-Processed Flexible Titanium Dioxide Memory Devices”
Provisional patent application filed 1/22/08serial # 51/022,534
Licensing & Collaboration Opportunity
Contact Information
Nadine Gergel-Hackett, [email protected]
David Gundlach, [email protected]
Curt Richter, [email protected]