Three-dimensional inkjet printing of electrically active materials

Additive Manufacturing (AM) for electronics (AME) offers the capability for a new generation of devices, with digitised customisation, remarkable design freedom, and low wastage. To achieve this, AM must enable excellent material properties, high resolution, multi-material processing, and scalabilit...

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Main Author: Nelson-Dummett, O.B.
Format: Thesis (University of Nottingham only)
Language:English
English
Published: 2025
Subjects:
Online Access:https://eprints.nottingham.ac.uk/80449/
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author Nelson-Dummett, O.B.
author_facet Nelson-Dummett, O.B.
author_sort Nelson-Dummett, O.B.
building Nottingham Research Data Repository
collection Online Access
description Additive Manufacturing (AM) for electronics (AME) offers the capability for a new generation of devices, with digitised customisation, remarkable design freedom, and low wastage. To achieve this, AM must enable excellent material properties, high resolution, multi-material processing, and scalability to attain industrial relevance. Inkjet printing (IJP) is one of the most mature technologies capable of such material properties and resolution, originating from graphical printing but now with several decades of research into functional materials behind it. IJP excels at multi-material processing and scalability, but major criticisms are the high anisotropy and inability to print truly 3D geometries, generally settling on 2.5D heterostructures instead. This work reports on a new finding that the anisotropy of conductivity in silver nanoparticle inks has been overestimated, and that it is mostly independent of the ink composition. Further, four polymer inks were investigated to pair with the silver ink as support and for high-quality dielectric contrast. Additionally, a novel method which requires no custom hardware – “Off the Grid” – was developed to remove aliasing which artificially decreases drop placement fidelity. This increases the accuracy of shape outlines and provides methods to control layer topology and negative space. This work was built upon to create 3D structures with uniquely complex geometries compared to previous IJP efforts, with single-drop-wide micropillars printed ≤ 4 mm high. After investigating the growth mechanism of the pillars, it was shown that they can lean without support, which enables the printing of helices and strut-based lattices. Finally, multimaterial prints are demonstrated with anisotropic silver elements within a dielectric matrix, which allows for easy control of the macro dielectric properties. Overall, this work pushes the boundaries of achievable geometries within AME and opens the potential for a wide range of functional devices to be inkjet-printed.
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language English
English
last_indexed 2025-11-14T21:04:25Z
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spelling nottingham-804492025-07-29T04:40:04Z https://eprints.nottingham.ac.uk/80449/ Three-dimensional inkjet printing of electrically active materials Nelson-Dummett, O.B. Additive Manufacturing (AM) for electronics (AME) offers the capability for a new generation of devices, with digitised customisation, remarkable design freedom, and low wastage. To achieve this, AM must enable excellent material properties, high resolution, multi-material processing, and scalability to attain industrial relevance. Inkjet printing (IJP) is one of the most mature technologies capable of such material properties and resolution, originating from graphical printing but now with several decades of research into functional materials behind it. IJP excels at multi-material processing and scalability, but major criticisms are the high anisotropy and inability to print truly 3D geometries, generally settling on 2.5D heterostructures instead. This work reports on a new finding that the anisotropy of conductivity in silver nanoparticle inks has been overestimated, and that it is mostly independent of the ink composition. Further, four polymer inks were investigated to pair with the silver ink as support and for high-quality dielectric contrast. Additionally, a novel method which requires no custom hardware – “Off the Grid” – was developed to remove aliasing which artificially decreases drop placement fidelity. This increases the accuracy of shape outlines and provides methods to control layer topology and negative space. This work was built upon to create 3D structures with uniquely complex geometries compared to previous IJP efforts, with single-drop-wide micropillars printed ≤ 4 mm high. After investigating the growth mechanism of the pillars, it was shown that they can lean without support, which enables the printing of helices and strut-based lattices. Finally, multimaterial prints are demonstrated with anisotropic silver elements within a dielectric matrix, which allows for easy control of the macro dielectric properties. Overall, this work pushes the boundaries of achievable geometries within AME and opens the potential for a wide range of functional devices to be inkjet-printed. 2025-07-29 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/80449/1/Nelson-Dummett%20Oliver%2010036749%20corrections.pdf text/plain en cc_by https://eprints.nottingham.ac.uk/80449/2/Nelson-Dummett%20Oliver%2010036749%20supplementary%20information.zip Nelson-Dummett, O.B. (2025) Three-dimensional inkjet printing of electrically active materials. PhD thesis, University of Nottingham. Additive manufacturing; Electronics; Inkjet printing; Nanoparticle inks; Polymer inks
spellingShingle Additive manufacturing; Electronics; Inkjet printing; Nanoparticle inks; Polymer inks
Nelson-Dummett, O.B.
Three-dimensional inkjet printing of electrically active materials
title Three-dimensional inkjet printing of electrically active materials
title_full Three-dimensional inkjet printing of electrically active materials
title_fullStr Three-dimensional inkjet printing of electrically active materials
title_full_unstemmed Three-dimensional inkjet printing of electrically active materials
title_short Three-dimensional inkjet printing of electrically active materials
title_sort three-dimensional inkjet printing of electrically active materials
topic Additive manufacturing; Electronics; Inkjet printing; Nanoparticle inks; Polymer inks
url https://eprints.nottingham.ac.uk/80449/