{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"d1b6b6f5a3f479affaa10456616a6ee979197827b1e2e83e3ecae702c57a18e3","created":"2026-10-03T07:17:58Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"c68a064b783ae5f12f0526c373fa9062e1c96eb3c582e6d7ee37d1ba066dadff","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"cm.contact-electrification.charge-mosaic","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Maps made with a sharp electrical probe show that after contact a surface is covered with patches of both positive and negative charge, about one ten-thousandth of a centimeter across, though the total charge is small. Why charge forms such a mosaic and what sets the patch size is unexplained.","posed_since":"2011","precise":"Kelvin probe force microscopy after contact (Baytekin et al., Science 2011) shows mosaics of positive and negative patches of lateral size about 1e-5 to 1e-4 cm with local densities far above the net charge density. Determine the mechanism (transfer of material carrying radicals and ions, heterogeneous surface chemistry, local discharges, flexoelectric polarization from contact strain) and the patch-size statistics, and how the mosaic relates to the net charge. An answer is a mechanism with a predicted patch-size distribution.","problem_ref":null,"references":"","settled_by":"Co-located charge and chemical mapping showing which species make up the patches, with patch statistics reproduced by a model.","status_note":"","title":"Origin of nanoscale bipolar charge mosaics on contacted surfaces","topic_ref":"6676ebb8ae9967cf0bd809e5691250afdfe45b670cf3dafe4fffa9bdff8cdab2"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5405b04e51b421258226c16a1e1e35ba04cc3f821a8ed8babb6b2a8a0ca0a7bf","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"b800f30bcb6014c77f63e146544d3ab6d01af76e40c3002dfa05d2bdbd43cdc9","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"tTmdGvpTeCweQFiX5xSJrCLITtAU5E65iCUF3Qtz4JIk84HWsDgE-nWCN2_wIGNPQo-ADL5_bKiEHk-7ZgnCAg"},"schema":"pubphys.envelope/1"},"record_hash":"5405b04e51b421258226c16a1e1e35ba04cc3f821a8ed8babb6b2a8a0ca0a7bf","leaf_index":919}