Initial Design

Our inaugural design was incorporated with a conveyer belt-like structure and press rollers so it should be called the Belt Design. A rough sketch of the Belt Design done beautifully by Rui Qing is shown below.

The Belt Design focuses on the movement of graphite on a piece of sticky tape which unwinds and rewinds, causing the tape to act like a conveyer belt. The various processes the machine will carry out on the graphite begin with the deposition of graphite at the leftmost structure on our machine. After graphite deposition onto sticky tape, we use a pulley that turns the orientation of the tape such that the sticky side of the tape will be facing down. Then, the graphite reaches a roller with tape on it facing upwards. The sticky sides of the two tapes will adhere together and pull apart at the roller, mimicking the motion of exfoliation. Following exfoliation, the graphite/graphene would be moved to the press roller where they will be firmly pressed onto a piece of silicon wafer. The silicon wafer is placed on a mobile container, which can be quickly removed and replaced by another container with a fresh piece of silicon wafer, ensuring a streamlined process. At this point, mechanical exfoliation would be completed!

Challenges of Initial Design

• The conveyer belt-like tape can be easily contaminated/ degraded in the open air
• The automation of the initial graphene deposition is hard to design
• The automation of the movement of the mobile containers is hard to design
• The number of exfoliations cannot be scaled up without making drastic changes to the mechanical parts
• The radius of the tape at the rewinders will change, causing the tape at the exfoliator and press roller to be not taut