Advanced materials and metamaterials · Advanced manufacturing

3D printing methods: metal, micro-scale and in orbit

What are the smallest sizes, largest outputs and main limits reported for these 3D printing methods and factory examples?

This comparison sets out three 3D printing methods and one factory example: metal printing, nanoscale printing, making parts in orbit and unattended factories. Each figure carries a claim type and, where the source gives one, its year and setting. A cell is left empty where the sources give no reliable public figure.

3D printing methods: metal, micro-scale and in orbit. Each cell shows a value, how well it is evidenced, and its sources.
OptionSmallest feature or part sizeSmallest feature or part size reported, with units (nm, µm, mm) and the conditions it was made under.Largest or fastest production reportedLargest or fastest output reported, with units (parts, km, units a year) and the year it refers to.Where it is used todayWhere the method or factory is used now, and whether that is a lab, a field test or a commercial setting.Main limitationThe main limitation reported in the cited sources, stated in one line.
Metal additive manufacturingNo reliable public figureGE's Auburn, Alabama plant reported its 30,000th additively manufactured fuel nozzle tip in early October 2018 (company-reported; no annual rate given).Reported, unverified[1]Aerospace fuel nozzle tips in mass production at GE's Auburn plant, per GE's October 2018 announcement (company-reported).Reported, unverified[1]Lack of DoD-approved qualification processes outside NASA standards (2024); metallurgical defects still limit most alloys (2023).Reported, unverified[2][3]
Two-photon lithographyAbout 120 nm resolution, and a 10 micrometre micro-bull printed in commercial resin (Osaka University lab work, 2001).Reported, unverified[4]No reliable public figureA 2023 review lists microelectronics, photonics, optoelectronics, microfluidics and plasmonic devices as fields of application.Reported, unverified[5]Shortage of two-photon polymerisable resins, which the 2023 review calls a bottleneck to growth.Reported, unverified[5]
In-space manufacturingNo reliable public figureMore than 11.9 km of ZBLAN optical fibre drawn in space between mid-February and mid-March 2024, including 1,141 m in one day (NASA-reported).Reported, unverified[6]Demonstration and research runs: a NASA fibre-drawing investigation (2024), a Varda W-1 capsule run that grew ritonavir crystals (company-reported) and a 2026 study of one orbit-grown InAsSb crystal.Reported, unverified[6][7][8]Fibre quality is not yet verified, and samples must return to Earth for testing (NASA, 2024).Reported, unverified[6]
Lights-out factoriesNo reliable public figureXiaomi's Beijing plant is stated to be able to produce 10 million flagship phones a year (capacity figure attributed to Xiaomi's founder, 2024; not measured output).Reported, unverified[10]Lux Research (2021) reports 22 FANUC lights-out factories; Xiaomi reported starting mass production at its Beijing plant on 9 July 2024.Reported, unverified[9][10]Manual inspection, maintenance and repair are cited as causes of planned downtime (Lux, 2021); no independent output or staffing figures are given.Reported, unverified[9]

What the table shows

  • Metal additive manufacturing has a company-reported figure of 30,000 printed fuel nozzle tips by early October 2018, with no annual rate and no feature size given.
  • Two-photon lithography reports a resolution of about 120 nm and a 10 micrometre model bull from 2001, and no verified production volume.
  • In-space manufacturing reports more than 11.9 km of optical fibre drawn in 2024, and its fibre quality is not yet verified.
  • The lights-out factory row has a company-stated capacity of 10 million phones a year and 22 FANUC factories reported in 2021, but no independent output or staffing figures.

Read with care

  • The figures come from different settings, including lab demonstrations, agency and company reports, and capacity claims, so they are not directly comparable.
  • Most production figures are company- or agency-reported and have not been independently verified.
  • Feature size and production volume measure different things, so the columns should not be read as a ranking.
  • The sources reviewed do not give verified cost or throughput figures for any row.

Sources

  1. company announcement
    Manufacturing Milestone: 30,000 Additive Fuel Nozzles
    GE Aerospace, 4 Oct 2018. Accessed 21 Oct 2026.
  2. government report
    Qualification and Certification of Powder Bed Fusion Additively Manufactured Components
    Travis J. Kneen. Defense Systems Information Analysis Center (DSIAC), 6 Mar 2024. Accessed 21 Oct 2026.
  3. other
    Recent Advances in Metal Powder-Based Additive Manufacturing
    Hong Wu, Yaojia Ren, Yingtao Tian et al.. Materials (MDPI), 26 May 2023. Accessed 21 Oct 2026.
  4. news
    New nano-technique hits the bull's-eye
    Physics World, 16 Aug 2001. Accessed 21 Oct 2026.
  5. peer reviewed paper
    Two decades of two-photon lithography: Materials science perspective for additive manufacturing of 2D/3D nano-microstructures
    Arun Jaiswal, Chandresh Kumar Rastogi, Sweta Rani et al.. iScience, 11 Mar 2023. Accessed 21 Oct 2026.
  6. government report
    Optical Fiber Production
    NASA, 25 Mar 2024. Accessed 21 Oct 2026.
  7. company announcement
    W-1
    Varda Space Industries, 12 Jun 2023. Accessed 21 Oct 2026.
  8. peer reviewed paper
    Microgravity-enabled growth of uniform InAsSb bulk single crystal
    Jidong Huang, Huaiwen Zheng, Zhigang Yin et al.. npj Microgravity, 25 Feb 2026. Accessed 21 Oct 2026.
  9. other
    Lights-Out Manufacturing: Still a Moonshot or a Closer Reality?
    Lux Research, 21 Jul 2021. Accessed 21 Oct 2026.
  10. news
    Xiaomi Starts Mass Producing Phones at New USD330 Million Smart Factory in Beijing
    Yicai Global, 9 Jul 2024. Accessed 21 Oct 2026.