Graphene Samples with AFM

Our last few days of research with Dr. McColgan consisted of starting a Graphene Project using the Atomic-Force Microscope (AFM). An AFM is a very high resolution type of scanning probe microscopy (SPM), with demonstrated resolution on the order of fractions of a nanometer, more than 1,000 times better than the optical diffraction limit. The Graphene is taken by ripping off layers of Graphite using Double Sided Adhesive Tape. Carbon atoms make up the structure of Graphene. It is important not to use locations on the sample that are too adhesive when looking at the samples. The tip will then stick to it when collecting data, and then not analyze it as well. The importance of analyzing Graphene is that it is conductive, manipulative, strong, an atom thick, and overall very cool to look at. It is important to note that Dr. Daniel Moriarty was extremely helpful and informative in our experiments with the AFM. We thank him very much. Below are some videos and pictures we took during our experiments with the Graphene.

Below is what the inside of the AFM looks like. This is where the majority of the experiment takes place. Bruker supplies the hardware and software for the AFM.

The AFM is very well insulated. Below we can see how well the AFM is insulated internally. This is because when collecting data the operator wants to reduce as much vibrations in the machine as much as possible so it does not skew the data. Examples of how this may affect the data are if there is a bunch of people walking around or near the AFM, the vibrations in the floor affect data collection. Speaking too loud or too close to the AFM produces sound waves and that vibrates the tip and affects data. Bumping into the machine shakes the AFM and skews data because it shakes the tip. To prevent any of these problems from occurring the AFM is insulated on the inside. 

 

To obtain our Graphene samples we needed to use a block of Graphite and rip off Graphene samples using Double Sided Adhesive Tape. The block of Graphite we used is shown below. The Graphite was supplied to us by Dr. McColgan and Dr. Hassel.

To collect our Graphene samples we needed to use Double Sided Adhesive Tape. A picture of the tape we used is shown below. 

Below is a picture of our Graphene sample we collected with the help of Dr. Moriarty. We used the Double Sided Tape to rip layers of Graphene off the block of Graphite. We placed the sample on a transparent glass slide and placed it in the AFM. We used a small vacuum feature inside the AFM to keep the glass slide in place while analyzing. Disregard the writing on the glass slide because it is writing from a previous experiment that the glass slide was probably used for before our experiments with it.

Below is a poster hanging in Roger Bacon on the first floor near the Key Auditorium. It is a research project by Andre Geim and Konstantin Novoselov regarding Graphene similar to the experiments we ran. It helped us better understand the research we were conducting.

We ran one sample of Graphene during our research, but have not received the software yet that is compatible to help us put it into this blog. We will be sure to update it once we do.

Below is a picture of Dr. Moriarty.

Future Research

For future research we plan on trying the following experiments:

1. We plan on trying to leave a piece of Double Sided Adhesive Tape on the block of Graphite overnight (or a longer period of time). This will let the tape sit on the Graphite and collect as much of a sample as possible without being disrupted. This may increase the accuracy of our sample and may help to collect more of the Graphene on the tape. 
2. Try taking layers of Graphene by applying the Double Sided Tape numerous times to the same section of the Graphite and then riping them off. This will make our sample thinker and better to use.
3. Try to find ways to burn the samples and increase the accuracy on collection of samples.
4. Collect more samples to increase accuracy, and to get us more familiar with the AFM.
5. Overall find better ways to take a Graphene sample.