Table 1. Manufacturing capability and current limitations for 3D printed CMU array presented here.

Process capabilities and limitations of the 3D nanoprinting process for neural probes developed in this work. PET, polyethylene terephthalate; PTFE, polytetrafluoroethylene.

Parameter	Capabilities	Limitations
Pitch (density)	200 μm min (2600 shanks/cm2)	Overspray, distortion of very narrow pillars. Overspray removal by PFIB can reduce the pitch down to 125 or 100 μm (i.e., shank densities of 6400–10,000/cm2); however, bed-of-nails effect may become a limiting factor as density increases.
Shank diameter	20–150 μm; shank tip diameter can be reduced to 10 μm.	Distortion during sintering. High-temperature sintering for longer shanks can help reduce the diameter further.
Shank length	0.1–3 mm	Further process optimization will lead to straight shank longer than 3–5 mm in length. Higher susceptibility to buckling failure is expected for high shank length–to–diameter ratios.
Shank count	512 demonstrated. More shank counts possible.	Shank footprint and size of connectors relative to animal being studied, time in postprocessing
Substrate material	Polyimide, alumina, glass, and PCB	Sintering temperature, adhesion. Flash photonic sintering or spot laser sintering can enable substrates such as PET and PTFE.