From AB Stacking to Twist: A Practical Route to Tunable Graphene Friction
Tribology Letters, cilt.74, sa.4, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 74 Sayı: 4
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s11249-026-02199-w
- Dergi Adı: Tribology Letters
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Atomic force microscopy, Molecular dynamics, Nanotribology, Structural lubricity, Twisted bilayer graphene
- İstanbul Ticaret Üniversitesi Adresli: Evet
Özet
Twisted bilayer graphene adds a simple—yet powerful—control knob to carbon interfaces: rotation. By changing the twist angle, a moiré superlattice emerges and reshapes the registry landscape that governs interfacial energy dissipation. Here, we combine lateral force microscopy (LFM) on transfer-processed bilayer graphene with molecular dynamics simulations of an idealized/defect-free Si/graphene sliding junction to quantify when twist control is robust and when it is masked by real-interface variability. Experimentally, kinetic friction coefficients are obtained from friction–load slopes measured at multiple locations. Among the twisted samples (2.3° to 10.2°), the mean kinetic friction coefficient increases from ≈ 0.034 to ≈ 0.078 (≈ 2.3×). Extending the comparison to the AB-stacked (0°) sample, synthesized via a distinct single-step growth route and treated as a qualitative baseline, yields an overall increase from ≈ 0.024 (≈ 3×), while spatial scatter highlights the sensitivity to local disorder, relaxation/strain, and surface residue. In parallel, molecular dynamics isolates intrinsic registry effects under controlled load, velocity, and pulling direction: the small-angle response is comparatively weak, whereas broader angle sampling reveals pronounced, non-monotonic changes and angle-specific anisotropy reaching a magnitude comparable to the experimental spread. Guided by moiré-based theory emphasizing registry averaging alongside finite-contact/boundary contributions, we interpret the experimental trend as an interplay between twist-engineered registry physics and extrinsic heterogeneity. Beyond establishing twist-tunable friction in a scalable carbon material, the study positions twisted bilayer graphene as a benchmark interface that bridges atomistic mechanisms and higher-level tribological observables, providing quantitative targets for multiscale modelling and design of graphene-coated sliding contacts.