Figure 2. Tuning of print parameters for graphene pillars.

(A) SEM images of pillars with 60 printed layers at print speeds of 1 mm/s, 0.5 mm/s, and 0.1 mm/s. (B) Pillar height as a function of print speed after 60 printed layers were deposited, as measured through SEM, indicating an increase in pillar height as print speed decreases due to an increase in dwell time of the nozzle around the loop at each layer. Inset showing three pillars printed at 0.3 mm/s, demonstrating the uniformity and repeatability of printing at this speed. (C) Lateral shift distance, d, in the printing file and corresponding printed layer. (D) Angle of the pillar with respect to the substrate as a function of d with the light orange showing standard deviation, highlighting the increased variability in the printed pillars at d greater than 3 μm. (E) SEM images of pillars with 60 printed layers with lateral shift distances, d, between each layer at 1 μm, 4 μm, and 7 μm, highlighting how the pillar leans further with each increase in spacing. All pillars, vertical and leaning, used a print path design of 75 μm diameter circles.