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Robotic four-dimensional pixel assembly of van der Waals solids

Nature Nanotechnology volume 17, pages 361–366 (2022)Cite this article

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Abstract

Van der Waals (vdW) solids can be engineered with atomically precise vertical composition through the assembly of layered two-dimensional materials1,2. However, the artisanal assembly of structures from micromechanically exfoliated flakes3,4 is not compatible with scalable and rapid manufacturing. Further engineering of vdW solids requires precisely designed and controlled composition over all three spatial dimensions and interlayer rotation. Here, we report a robotic four-dimensional pixel assembly method for manufacturing vdW solids with unprecedented speed, deliberate design, large area and angle control. We used the robotic assembly of prepatterned ‘pixels’ made from atomically thin two-dimensional components. Wafer-scale two-dimensional material films were grown, patterned through a clean, contact-free process and assembled using engineered adhesive stamps actuated by a high-vacuum robot. We fabricated vdW solids with up to 80 individual layers, consisting of 100 × 100 μm2 areas with predesigned patterned shapes, laterally/vertically programmed composition and controlled interlayer angle. This enabled efficient optical spectroscopic assays of the vdW solids, revealing new excitonic and absorbance layer dependencies in MoS2. Furthermore, we fabricated twisted N-layer assemblies, where we observed atomic reconstruction of twisted four-layer WS2 at high interlayer twist angles of ≥4°. Our method enables the rapid manufacturing of atomically resolved quantum materials, which could help realize the full potential of vdW heterostructures as a platform for novel physics2,5,6 and advanced electronic technologies7,8.

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Fig. 1: Robotic four-dimensional pixel assembly.
Fig. 2: Automated vacuum assembly of vdW heterostructures.
Fig. 3: Comprehensive optical assay of N-layer stacked MoS2.
Fig. 4: Reconstruction in twisted four-layer WS2.

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Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request. Source data are provided with this paper.

Code availability

All code used in this work is available from the corresponding authors upon reasonable request.

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Acknowledgements

Primary funding for this work came from the National Science Foundation through the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM) under Cooperative Agreement No. DMR-2039380. It was partially supported by the Air Force Office of Scientific Research MURI project (FA9550-18-1-0480). Materials growth performed by C.P. was partially supported by the Samsung Advanced Institute of Technology. This work made use of shared facilities at the University of Chicago Materials Research Science and Engineering Center, supported by the National Science Foundation under Award Number DMR-2011854. This work made use of the Pritzker Nanofabrication Facility, which receives partial support from the SHyNE Resource, a node of the National Science Foundation’s National Nanotechnology Coordinated Infrastructure (NSF ECCS-2025633), and the Searle Cleanroom, which was procured through funding generously provided by The Searle Funds at The Chicago Community Trust (Grant A2010-03222). A.J.M. was supported by the Kadanoff-Rice Postdoctoral Fellowship of the University of Chicago MRSEC (DMR-2011854). A.Y. is supported by the Department of Defense (DoD) through the National Defense Science and Engineering Graduate (NDSEG) Fellowship Program. A.R. and the electron microscopy facility at the Cornell Center for Materials Research are supported by NSF-MRSEC grant DMR-1719875. The Titan microscope at Cornell was acquired with the NSF MRI grant DMR-1429155. This work made use of the Michigan Center for Materials Characterization. R.H. acknowledges support from the W. M. Keck Foundation. S.H.S. acknowledges support from the Army Research Office (W911NF-17-S-0002). A.A.H and R.S. acknowledge support from the Army Research Office (W911NF-20-1-0217). We also acknowledge funding from the Air Force Office of Scientific Research (FA9550-16-1-0347) and the Department of Energy (DOE) through the EFRC for Novel Pathways to Quantum Coherence in Materials.

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Author notes

  1. Andrew J. Mannix

    Present address: Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA

  2. These authors contributed equally: Andrew J. Mannix, Andrew Ye.

Authors and Affiliations

  1. James Franck Institute, University of Chicago, Chicago, IL, USA

    Andrew J. Mannix, Myungjae Lee & Jiwoong Park

  2. Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA

    Andrew Ye, Alexander A. High & Jiwoong Park

  3. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, USA

    Suk Hyun Sung & Robert Hovden

  4. School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA

    Ariana Ray & David A. Muller

  5. Department of Chemistry, University of Chicago, Chicago, IL, USA

    Fauzia Mujid, Chibeom Park, Jong-Hoon Kang & Jiwoong Park

  6. Department of Physics, University of Chicago, Chicago, IL, USA

    Robert Shreiner

  7. Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, IL, USA

    Alexander A. High

  8. Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, USA

    David A. Muller

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Contributions

A.J.M. and J.P. conceived the main ideas of this work. A.J.M. and A.Y. built the VAR and designed the polymer stamps. C.P. and A.J.M. formulated the TSL patterning technique. A.Y., F.M., C.P. and J.-H.K. grew the MOCVD TMD materials used in this work. A.Y. and A.J.M. manufactured the presented vdW solids using the VAR. A.Y. and M.L. acquired and analysed the optical measurements. A.Y. wrote the code and analysed the results from the TMM optical calculations and performed the laser confocal scanning microscopy and Raman mapping measurements. A.R. collected the FIB cross-section and STEM data. S.H.S. carried out the SAED and DF-TEM analysis of the twisted 4 L WS2 structure, and performed the multislice simulation of the rigid twisted 4 L WS2 structure. A.Y. and R.S. fabricated the exfoliated samples, and R.S. measured their cryogenic optical response. A.A.H. and R.S. analysed and discussed the cryogenic measurements on the exfoliated heterostructure. D.A.M. and R.H. assisted in the discussion and interpretation of the STEM and TEM data. A.J.M., A.Y. and J.P. wrote the paper with input from all co-authors.

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Correspondence to Jiwoong Park.

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Nature Nanotechnology thanks Jeehwan Kim and Zhi-Bo Liu for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Discussion, Table 1 and Figs. 1–19.

Supplementary Video 1

In situ view of the vacuum assembly robot manufacturing a 16-tile MoS2 structure. Speeded up ×100 (~40 min from start to finish in real time).

Supplementary Data 1

Calculation of reflection using the transfer matrix method for 1–17 layers of MoS2. Used in generating Supplementary Fig. 12.

Supplementary Data 2

Calculation of transmission using the transfer matrix method for 1–17 layers of MoS2. Used in generating Supplementary Fig. 12.

Source data

Source Data Fig. 3

Extracted absorption spectra (and constituent transmission and reflection spectra), along with photoluminescence spectra (averaged over 4 points per thickness region) from the 16-tile MoS2 sample in Fig. 3.

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Mannix, A.J., Ye, A., Sung, S.H. et al. Robotic four-dimensional pixel assembly of van der Waals solids. Nat. Nanotechnol. 17, 361–366 (2022). https://doi.org/10.1038/s41565-021-01061-5

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