Market Overview:
This composite, made of multi-walled carbon nanotubes (MWNT) and cellulose nanocrystals (CNC), provides a safer substitute for silicon in microelectromechanical system (MEMS) devices. The global MEMS market was $11.9 billion in 2015, and is expected to grow to $18 billion by 2020 due to increased interest in wearable technology and the automotive industry. Traditionally MEMS devices are made out of doped-silicon. However, the use of doped-silicon poses safety, economic and environmental hazards due to high energy costs, particle waste left in the air and use of harmful chemicals in the manufacturing process. To provide a safer alternative, Clemson University researchers have developed a composite film that lowers environmental and health concerns while maintaining the necessary electrical conductivity of the film for MEMS device production. By combining the outstanding strength and biocompatibility of cellulose nanocrystals with the stiffness, strength and electrical properties of carbon nanotubes, a safer alternative is achieved.
Application Stage of Development
MEMS device manufacturing Proof-of-concept
Advantages
• Utilizes carbon nanotubes added to cellulose, creating a composite with a conductivity at the semiconductor level
• Provides film with anisotropic properties, providing increased utility compared to current silicon based
MEMS devices
• Eliminates need for silicon in the MEMS manufacturing process, reducing workplace and environmental hazards
Technical Summary
This biocompatible composite was created by preparing an aqueous mixture of CNC and MWNT. CNC is used due to similar mechanical properties and surface chemistry to silicon, and can be manufactured into MEMS devices by photolithography. MWNT provide high conductivity, strength, and stiffness to the composite. The aqueous mixture is sonicated to create a uniform dispersion, which is processed into a film by blade coating. The addition of MWNT to CNC is shown to greatly increase the elastic modulus and conductivity. The composite exhibits anisotropic properties, where the conductivity is sufficient for static charge dissipation in the semi-conductive range in the machine direction.
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Inventors: Christopher Kitchens, Mingzhe Jiang, Byron Villacorta
Patent Type: Provisional
CURF Ref No: 2016-031