The Superiority Of Graphene Usage In Flexibility Of Touch Screens

Abstract

The project aim is to investigate the mechanical strength of the two-different materials graphene and indium tin oxide used in manufacturing of touch screens. Indium tin oxide is one of the widely used transparent conducting oxides in majority of smartphones, tablets and other devices occupied with touch screens. Graphene emerging as a promising material to replace indium tin oxide in touch screen technology. Research is conducted by structured procedures to discover material strengths in this project. Both the indium and graphene are tested by touch screen force tester and the tested data will be collected and analyzed. Survey is conducted by taking the opinion from experts in testing the strength of materials.

Introduction

The modern electronic gadgets are equipped with touch screen for easy access and to work efficiently. Flexible touch screens and displays, printable electronics, flexible transistors and thin film photovoltaics are the applications which uses flexible transparent conductors such as graphene, indium tin oxide, conductive polymers, carbon nanotubes and nanowires. The intension of this research is to study the flexible natures of both graphene and indium tin oxide which can be utilized in touch screen manufacturing. Researchers are claiming that graphene is set to revolutionize the smartphone industry by replacing the current touch screen technology. Among all the flexible transparent conductors graphene has attracted great attention due to its 2D nature, excellent electron transfer behavior, high transparency and chemical and thermal stability because of all these properties it can be used in different fields. Moreover, it has ultrahigh flexibility. On the other hand, indium tin oxide is traditionally used in the manufacture of touch screens in the present industry. Indium tin oxide is of high cost and due to its scarcity in the supply makes a graphene better transparent conductor, besides all this indium tin oxide suffers from its ceramic nature as well, which limits its mechanical flexibility. All these factors influence to conduct a research to investigate the mechanical strength of the graphene compared with the indium tin oxide to provide flexible strength in building touch screens. Research will be conducted to test the mechanical flexibility of graphene and indium tin oxide sheets by placing in Touch-screen Force Tester and subjected to various Newton forces. The data is recorded for both the sheets and stored in a table. Furthermore, for detailed inspection, survey is carried by taking the opinion of a group of experts in material testing who are qualified in judging the strength of graphene and indium tin oxide with several questions and are tabulated.

Background

The raw material used to make touchscreens for smartphones, tablet PCs and other gadgets is indium tin oxide. These films used as a transparent conductive electrode, especially with organic liquid crystal displays, LED displays and TET screens. For all these reasons it is a common practice to use indium tin oxide films, since they best satisfy the requirements as far as conductivity and transmission properties are concerned. In contrast indium tin oxide film is a brittle crystalline material and when stressed film may fracture, as a result conductivity will be dropped and thus limiting its use in some application which require some flexibility. Moreover, these films are highly expensive in present market. According to new studies supplies of these materials will run out in the next decades which could lead towards a serious manufacturing problem. To overcome all these problems scientists are successful in the discovery of new alternative material called graphene.

Graphene was discovered in 2004 by repeatedly peeling highly oriented graphite with cellophane tape. Since the cost of graphite is less compared to indium. A single sheet of graphene is a zero-band gap semiconductor with extremely high carrier mobility’s that can only absorbs 2.3% of visible light. Graphene provides several advantages like weight, robustness, flexibility and chemical stability over indium tin oxide. The companies like Fujitsu and Eikos Inc. have already started implementing graphene films in their touchscreen technologies. This research will be going to demonstrate flexibility of graphene films which can be used in touchscreen because graphene display best property for alternative in touch screen technologies. This research is intended to get highest flexibility nature of graphene which is better than and indium tin oxide in manufacturing of the touch screens. Research will help in mass production of graphene for future technologies.

Methodology

The research will be conducted in two steps.

1. The experiment will be conducted by investigating the flexibility of two films graphene and indium tin oxide by placing them in touch screen force tester.
2. A survey is carried to determine the strengths of two materials suitable for implementing in touch screen technologies by the experts who are certified in testing the strengths of these two materials.

In first method experiment is conducted in a laboratory with detailed inspection. In this method we are using a device called touchscreen force tester. This device is used to measure the flexibility of different materials by applying desired force on particular area.

Apparatus required:

1. Touchscreen force tester device.
2. Sample of indium tin oxide film of thickness 200nm, width 5cm, length 5cm.
3. Sample of graphene film of thickness 200nm, width 5cm, length 5cm.
4. Tools to handle the samples in care.
5. Power supply.

Graphene film samples are placed in touchscreen force tester device and force is applied in Newton. The sample film is marked and 1Newton force is applied on that marked area and damage rate in that area is recorded. This process continues for different Newton forces from 1Newton to 5 Newton in different areas of the film. Similar procedure is carried out for indium tin oxide films by applying the 1Newton to 5Newton force in the specific marked area and damage rate for each applied force is recorded. Data from both the procedures will be recorded and tabulated for further investigation. Experiment should be carried out with help of technician who is proficient in handling the device and carrying out procedure as per the guidelines mentioned. After this experiment both samples should be taken good care and preserved for the future verification.

Secondly, a survey is conducted to examine the strength and the flexibility of the two films. For this a dedicated website is created and a group of experts will be contacted each will be assigned an individual portal to report. A significance and specific instructions of the survey is explained to each through the website. Freedom is given to all the experts to judge the flexibility of the material in their own technique. Arrangement should be made to provide experts what they required to examine this survey. After all this procedure a period of 30 days is given for the examining flexibility of the two films. Lastly, all the experts involved in the survey is being asked the set of 4 questions related to the flexibility and strengths of the film using the assigned portals.

Data analysis

In first stage of research investigation conducted in laboratory gives damage rate for both graphene sample film and indium tin oxide sample film. The rating is given according to range of 1-10. For minimum damage of films for the applied force rate of damage will be recorded as 1 and for maximum damage of films the rate of damage will be recorded as 10. In this method which film got maximum damage rate and minimum damage rate will be recorded at the end. Survey method is conducted as a part of second stage in this research methods where opinion of all the experts are converted into numerical data submitted in their individual portal. In this method also rating is done from 1-10 scale for each question. Experts will be given their ratings in terms of flexibility they observed in these two films. But here for each question rating 10 will be maximum rating for question 1 will be given for minimum rating. The question which has maximum rating will be considered as the efficient material which can be used in manufacturing of touchscreens. These rating will be converted in the form of percentage by taking all the experts rating in to the account and percentage for each rating will be recorded in the table. Results obtained from both the methods helps to draw a conclusion for the flexibility of the two films graphene and indium tin oxide. Analysis of this research is that graphene will be emerging as a more flexible material than indium because of the natural properties of graphene which will be discussed in theoretical analysis.

Theoretical analysis

Graphene is a two-dimensional form of carbon with a honeycomb-shaped lattice structure. Thickness of graphene is around one atom hence the single carbon bonds can be rotated and can form covalent bonds. These covalent bond formed is of very strong which in turn gives toughness and flexibility for the graphene. All these chemical nature contributing flexibility for the graphene.

Conclusion

The data we got from both experiment and survey determines the flexibility nature of the two materials graphene and indium tin oxide. The damage to the film from applied force clearly gives the flexible nature of the films. If the rating given is 1-3 than that film is having higher flexibility, if the rating decreases towards 10 than film flexibility will continues to decrease. In addition, results from survey clearly indicates whether graphene can be an effective material to replace indium tin oxide in touchscreen manufacturing technology. The percentage rating calculated from experts is high for 7-10 than that film will be having high flexibility. By comparing all such rating from two stages we will get to know which material is best suit in touchscreen manufacturing. All these results indicate if graphene is a better material in flexibility than it will be an initiative for implementing in touchscreen technology. Graphene is still not manufactured in large scale because of the uncertainty of its flexible nature.

Finally, in this research project if graphene emerged as more flexible than indium tin oxide it can result in a mass production of graphene to greater extent.