1. Variability of Resistance of Kirigami Graphene Under Strain
David Zhang1, Keong Yong2, SungWoo Nam2
1Department of Electrical and Computer Engineering
2Department of Mechanical Science and Engineering
Motivation
Product
9.44 mm by 3.68 mm piece
.16mm thick holes
This piece is in the middle of laser cutting
18.88mm by 7.36 mm piece
.32 mm thick holes
Graphene is like a wonder material!
Highest electron mobility
Strongest material: 100X stronger than steel
Thinnest possible material (single atom)
Flexible at nanoscale (6-15 % strain)
Recent developments in wearable sensors require robust strain sensor with larger range
(Human body range of motion ~ 60%)
Make an ultra-thin, conformal graphene device.
Develop technique to fabricate nanomaterial-based devices without complexed equipment or facility.
Data Collection
The laser cutter from Innovation Studio has three settings: Speed, Power, and Frequency.
Our goal is to have the optimum laser conditions so that the piece can be cut with the least burn.
Frequency is kept at 100% for best result. So, we need to find the optimum mix of the other two variables.
Background
Graphene is so thin that it is usually transferred to a substrate to support structural stability
Strain sensors are in thin, long, and flexible patterns.
Under heat, pressure, and strain, their shape allows them to change resistance.
Research Plan
Graphene synthesis with CVD
Design kirigami patterns for graphene device
Find a suitable substrate that can protect graphene without limiting its properties.
Develop a method to cut patterns into the substrate without the use of a cleanroom.
Transfer graphene on the flexible substrate
Characterize the graphene device
Skills & Possible Future Work
I learned to read literature review before research
I can record data and design new methods to laser cut Kapton sheets.
Gauge Factor for kirigami graphene has yet to be discovered
Current Progress
Synthesized uniform large-area high quality graphene (Raman Spectra is good)
Developed a technique to laser cut fine features on polyimide films.
.25mm Kapton is strong, flexible, and thin. We attempted to use laser cutting, but there were burns.
References
Pu, Jean; Wang, Xiaohong; Xu, Renxiao & Komvopoulos, Kryiakos. Highly Stretchable Microsupercapacitor Arrays with Honeycomb Structures for Integrated Wearable Electronic Systems. ACSNano. 2016, 10,
Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin & Tour, James M. Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates. ACSNano. 2016, 10,
Special thanks to Keong Yong for guiding me in his research with literature reviews, designing experiments, and introducing me to Nam’s group. He is in the early steps of tinkering with graphene in hope to discover properties that could be used in chemical and biosensing.
Acknowledgement