Nanoencoders based on arrays of single nanotube emitters

Linear encoders for nanoscale position sensing based on single multiwalled carbon nanotube (MWNT) arrays are investigated from experimental, theoretical, and design perspectives. Vertically aligned single MWNTs are realized using a combination of e-beam lithography and plasma-enhanced chemical vapour deposition (PECVD) growth. Field emission properties of the array are investigated inside a scanning electron microscope (SEM) equipped with a 3-DOF nanorobotic manipulator with nanometer resolution functioning as a scanning anode. Lateral position of the scanning anode is sensed from the emission distribution. High resolution (best: 12.9 nm; practical: 38.0 nm) for lateral position sensing around an emitter has been realized.