奥地利科学技术研究所Juan Carlos Sobarzo团队发现了相同材料自发有序为摩擦电序。2025年2月19日出版的《自然》杂志发表了这项成果。

当两种绝缘中性材料接触和分离时，它们会交换电荷。长期以来，实验表明，这种“接触带电”是可传递的，不同的材料根据所获得的电荷符号排列成“摩擦电序”。同时，该效果也受到不可预测性的困扰，阻碍了人们对机制的共识，并对序隐含的规律和原因产生了怀疑。

研究组揭示了接触带电的不可预测性和有序性之间意想不到的联系：名义上相同的材料最初会随机和不可逆地交换电荷，但经过反复的实验，有序地形成摩擦电序。研究发现，这种演变是由接触行为本身驱动的——历史上接触次数较多的样本对接触次数较少的样本带负电荷。在最小模型中捕获这种“接触偏差”，研究组在数值模拟中重建了初始随机性和最终顺序，并通过实验迫使其选择的摩擦电序出现。

通过一系列表面敏感技术来寻找接触产生的潜在变化，结果只发现了纳米级形态变化的证据，这表明了一种与力学密切相关的机制。该研究结果强调了接触史在接触带电中的中心地位，并表明关注长期困扰这种效应的不可预测性可能是理解它的关键。

附：英文原文

Title: Spontaneous ordering of identical materials into a triboelectric series

Author: Sobarzo, Juan Carlos, Pertl, Felix, Balazs, Daniel M., Costanzo, Tommaso, Sauer, Markus, Foelske, Annette, Ostermann, Markus, Pichler, Christian M., Wang, Yongkang, Nagata, Yuki, Bonn, Mischa, Waitukaitis, Scott

Issue&Volume: 2025-02-19

Abstract: When two insulating, neutral materials are contacted and separated, they exchange electrical charge1. Experiments have long suggested that this ‘contact electrification’ is transitive, with different materials ordering into ‘triboelectric series’ based on the sign of charge acquired2. At the same time, the effect is plagued by unpredictability, preventing consensus on the mechanism and casting doubt on the rhyme and reason that series imply3. Here we expose an unanticipated connection between the unpredictability and order in contact electrification: nominally identical materials initially exchange charge randomly and intransitively, but—over repeated experiments—order into triboelectric series. We find that this evolution is driven by the act of contact itself—samples with more contacts in their history charge negatively to ones with fewer contacts. Capturing this ‘contact bias’ in a minimal model, we recreate both the initial randomness and ultimate order in numerical simulations and use it experimentally to force the appearance of a triboelectric series of our choosing. With a set of surface-sensitive techniques to search for the underlying alterations contact creates, we only find evidence of nanoscale morphological changes, pointing to a mechanism strongly coupled with mechanics. Our results highlight the centrality of contact history in contact electrification and suggest that focusing on the unpredictability that has long plagued the effect may hold the key to understanding it.

DOI: 10.1038/s41586-024-08530-6

Source: https://www.nature.com/articles/s41586-024-08530-6