Machining of 2D material by ultrasonic embossing

• Main Author: Seow, Colvis Wei Chen
• Other Authors: Hong Li
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/166953
• Institution: Nanyang Technological University

As popularity of 2D material has increased over the years since the discovery of Graphene in 2004, their usage in the field was also characterised by their properties. Graphene for its mechanical properties like high strength, stiffness, toughness, and conductivity. Hexagonal Boron Nitride for its chemical inertness and electrical insulation properties. By working with 2D materials in the nanoscale, the author hopes to understand and gauge their properties in the quantum scale. Hence, in this report the author will share the process of creating nanostructures and nanodots from Graphene and Hexagonal Boron Nitride with the use of ultrasonic embossing on substrate materials like silver and copper whilst exploring the parameters used to obtain the highest yield of nanostructures. From previous studies and research on similar topics, the fundamental method of choice for sample preparation will be the top-down mechanical exfoliation. More commonly known as the “Scotch-tape” method. The author will also be testing out other methods of sample preparation for bulk materials that are already in the powdered form. With existing studies of ultrasonic embossing on other types of 2D materials, the author started off with a familiarisation process with the type and characteristics of the materials and equipment. On the other hand, skill sets employed during the experiment such as delicate handling of samples and skilful usage of the scanning electron microscope needs to be gained through repeated practices. The results obtained from the ultrasonic embossing confirms that the greatest yield of nanostructures falls within the range of 1300N – 1400N for welding and holding forces and embossing amplitude ranging from 17% - 22%.