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Abstract Electrohydrodynamic jet (e‐jet) printing is a high‐resolution additive manufacturing technique that holds promise for the fabrication of customized micro‐devices. In this companion paper set, e‐jet printing is investigated for its capability in depositing multilayer thin‐films with microscale spatial resolution and nanoscale thickness resolution to create arrays of 1D photonic crystals (1DPC). In this paper, an empirical model for the deposition process is developed, relating process and material parameters to the thickness and uniformity of the patterns. Standard macroscale measurements of solid surface energy and liquid surface tension are used in conjunction with microscale contact angle measurements to understand the length scale dependence of material properties and their impact on droplet merger into uniform microscale thin‐films. The model is validated with several photopolymer inks, a subset of which is used to create pixelated, multilayer arrays of 1DPCs with uniformity and resolution approaching standards in the optics manufacturing industry. It is found that the printed film topography at the microscale can be predicted based on the surface energetics at the microscale. Due to the flexibility in design provided by the e‐jet process, these findings can be generalized for fabricating additional multimaterial, multilayer micro‐ and nanostructures with applications beyond the field of optics.
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Subtractive Patterning of Nanoscale Thin Films Using Acid‐Based Electrohydrodynamic‐Jet Printing
Abstract As an alternative to traditional photolithography, printing processes are widely explored for the patterning of customizable devices. However, to date, the majority of high‐resolution printing processes for functional nanomaterials are additive in nature. To complement additive printing, there is a need for subtractive processes, where the printed ink results in material removal, rather than addition. In this study, a new subtractive patterning approach that uses electrohydrodynamic‐jet (e‐jet) printing of acid‐based inks to etch nanoscale zinc oxide (ZnO) thin films deposited using atomic layer deposition (ALD) is introduced. By tuning the printing parameters, the depth and linewidth of the subtracted features can be tuned, with a minimum linewidth of 11 µm and a tunable channel depth with ≈5 nm resolution. Furthermore, by tuning the ink composition, the volatility and viscosity of the ink can be adjusted, resulting in variable spreading and dissolution dynamics at the solution/film interface. In the future, acid‐based subtractive patterning using e‐jet printing can be used for rapid prototyping or customizable manufacturing of functional devices on a range of substrates with nanoscale precision.
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- PAR ID:
- 10484574
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small Methods
- ISSN:
- 2366-9608
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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