Science Advances

The PDF file includes:

• Supplementary Text
• Fig. S1. Schematics of the Al₂O₃-CNT SNE fabrication procedure.
• Fig. S2. Diagram and optical images of unpackaged LED chiplets (UT170-31, CREE) used in picking and placing demonstration.
• Fig. S3. Atomic force microscopy (AFM) system used for indentation tests with external voltages.
• Fig. S4. Adhesion on/off ratio (ratio of pull-off force with an external voltage to that without voltage) of Al₂O₃-coated surfaces with and without SNE on a TiN layer.
• Fig. S5. Optical microscope images of a paper towel showing its microscopically porous and rough surface.
• Fig. S6. Transmission electron microscopy images of Al₂O₃ coating on individual CNT fibers via ALD with different numbers of cycles.
• Fig. S7. Al₂O₃-CNT SNEs grown with different CVD procedures, exhibiting different CNT densities.
• Fig. S8. Pull-off forces of Al₂O₃-CNT SNEs with different heights according to applied voltages.
• Fig. S9. Pull-off forces of Al₂O₃-CNT SNEs measured by AFM using a 4 μm Pt-coated spherical tip with different applied external voltages and preloads.
• Fig. S10. Pull-off forces of Al₂O₃ coated TiN layer measured by AFM using a 4 μm Pt-coated spherical tip with different applied external voltages and preloads.
• Fig. S11. Pull-off forces of SNE measured by AFM indentation using a 10-μm SiO₂ spherical tip with and without the shear motion.
• Fig. S12. Schematics of adhesion tests on an Al₂O₃-TiN surface using a microsphere.
• Fig. S13. Contact mechanics modeling of adhesion between an Al₂O₃-CNT nanocomposite surface and a microsphere.
• Fig. S14. Adhesive and gravitational forces along the object size.
• Fig. S15. Optical microscope images of PS microspheres picked from a spin-coated layer using a patterned SNE surface and placed on a silicon wafer surface, under on or off electrical voltage conditions.
• Fig. S16. Picking-and-placing of stainless steel (SS) microparticles, sized 15-45 μm, using a 200 μm by 200 μm Al₂O₃-CNT SNE, from a silicon wafer to a transparent substrate.
• Legends for movies S1 and S2

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Other Supplementary Material for this manuscript includes the following:

• Movie S1 (.mp4 format). Picking and placing of an unpackaged micro-LED chiplet using an Al₂O₃-CNT nanocomposite electroadhesive (side view).
• Movie S2 (.mp4 format). Picking and placing of a piece of paper towel using an Al₂O₃-CNT nanocomposite electroadhesive and polydimethylsiloxane block.