A Low-Cost Planar Inkjet-Printed Carbon Nanotube Field Effect Transistor for Sensor Applications

The semiconductor based transistor is the most essential building block of electronic components, computing applications, and sensors. However, the fabrication of this primary electronic element is complex and costly, especially when considering flexible electronics for bio-sensing applications. This paper proposes a planar inkjet-printed carbon nanotube field effect transistor (CNTFET) on paper and polyethylene terephthalate (PET) substrate to reduce the complexity of the system and lower the cost of conventional fabrication schemes. Single walled carbon nanotubes (SWNTs) are being used as semi-conductive ink for an inkjet-printer to facilitate and fabricate two types of transistors. Both thin (0.3 mm gate separation) and thick (0.5 mm gate separation) transistors with wide (4 mm) and narrow (2 mm) channel length have shown nearly linear characteristics of resistivity for a range of applied gate voltages. Our mathematical model based on experimental results shows great usefulness of the proposed inkjet-printed CNTFET for various electronic applications including but not limited to bio-sensors, healthcare measurements, and circuits.