Room temperature, cavity-free capacitive strong coupling to mechanical motion Puglia, Denise ; https://orcid.org/0000-0003-1144-2763 Odessey, Rachel H Burns, Peter Luhmann, Niklas Schmid, Silvan Higginbotham, Andrew P ; https://orcid.org/0000-0003-2607-2363 The back-action damping of mechanical motion by electromagnetic radiation is typically overwhelmed by internal loss channels unless demanding experimental ingredients such as superconducting resonators, high-quality optical cavities, or large magnetic fields are employed. Here we demonstrate the first room temperature, cavity-free, all-electric device where back-action damping exceeds internal loss, enabled by a mechanically compliant parallel-plate capacitor with a nanoscale plate separation and an aspect ratio exceeding 1,000. The device has 4 orders of magnitude lower insertion loss than a comparable commercial quartz crystal and achieves a position imprecision rivaling optical interferometers. With the help of a back-action isolation scheme, we observe radiative cooling of mechanical motion by a remote cryogenic load. This work provides a technologically accessible route to high-precision sensing, transduction, and signal processing. American Chemical Society 2025 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/19026 Puglia D, Odessey RH, Burns P, Luhmann N, Schmid S, Higginbotham AP. Room temperature, cavity-free capacitive strong coupling to mechanical motion. <i>Nano Letters</i>. 2025;25(7):2749-2755. doi:<a href="https://doi.org/10.1021/acs.nanolett.4c05796">10.1021/acs.nanolett.4c05796</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1021/acs.nanolett.4c05796 info:eu-repo/semantics/altIdentifier/issn/1530-6984 info:eu-repo/semantics/altIdentifier/e-issn/1530-6992 info:eu-repo/semantics/altIdentifier/wos/001415246000001 info:eu-repo/semantics/altIdentifier/arxiv/2407.15314 info:eu-repo/semantics/openAccess