Cellulose nanocrystals (CNCs) hold great promise for lubrication, but face hindrances from high surface polarity and low tribochemical reactivity. Here, chlorinated CNCs (CNCsCl) were synthesized through modifying CNCs with thionyl chloride by a halogen exchange reaction. The effects of chlorination on crystallinity, morphology, and thermal stability were characterized, and the optimal chlorination conditions (78 °C, 2 h), yielding CNCsCl3, were determined. CNCsCl3 retained a high crystallinity (79.5
The friction performance of surgical tools is a key mechanical factor governing cutting resistance and tissue–instrument interactions. Reducing excessive interfacial friction is therefore important for improving the mechanical cutting performance of surgical instruments. To enhance this, bio-inspired micro-textures were fabricated on different regions (blade face, cutting edge, entire surface) of disposable T10 scalpels via femtosecond laser processing, yielding S-Face, S-Edge, and S-All textured blades. A custom-built flexible material cutting platform was used to evaluate interfacial friction responses under multi-angle and multi-speed conditions. Results show that blade face texturing (S-Face) notably improves hydrophobicity (contact angle > 145°) and reduces the real contact area, resulting in pronounced friction reduction, whereas edge texturing (S-Edge) forms full contact in the stress concentration zone, slightly increasing friction. S-Face maintains low friction across all tested parameters, demonstrating excellent adaptability. Mechanism analysis reveals that the micro-textures synergistically regulate friction via three pathways: (1) altering contact morphology to limit contact area, (2) inducing a Cassie–Baxter wetting state to weaken adhesion, and (3) perturbing stress distribution to reduce indentation depth and hysteresis energy dissipation. This study proposes a scalable surface functionalization strategy for surgical scalpels, providing theoretical and experimental references for anti-friction modification and multi-scenario adaptation of medical instruments. These findings establish a mechanical basis for friction-reducing surface design of surgical scalpels, while its potential benefits for tissue preservation require further validation using biological tissue models.
CrN coatings are extensively utilized in industrial applications due to their high hardness and excellent wear resistance, yet their performance under elastohydrodynamic lubrication (EHL) remains insufficiently understood. This study systematically investigates the tribological properties of a CrN-coated GCr15 steel under EHL contact by combining experiments with molecular dynamics (MD) simulations. The results show that under pure rolling conditions, the deposited CrN coating does not affect the oil film thickness. However, under pure sliding conditions, the low surface energy of the coating leads to surface slippage, resulting in a 31.7
The 6082-T6 aluminium alloy is widely used in engineering applications but its broader deployment is restricted by poor wear and friction resistance. Solid lubricants such as molybdenum disulphide (MoS2) can improve its tribological performance; however, their effectiveness is limited by short service life and the need for frequent replenishment. Laser surface texturing (LST) has proven effective in extending lubricant lifespan, yet the influence of tribological system configuration on textured, solid-lubricated aluminium surfaces remains insufficiently understood. In this study, the combined effects of groove texture density (TD) and pin-on-disc configuration on the tribological behaviour of MoS2-coated 6082-T6 aluminium alloy were systematically investigated. Groove patterns with TD values ranging from 25 to 100% were fabricated using an infrared nanosecond pulsed fibre laser, and MoS2 coatings were applied by spraying. Tribological performance was evaluated under dry and lubricated conditions using three configurations: textured pin, textured disc, and both pin and disc textured. Finite element analysis was conducted to examine the influence of surface texturing and groove orientation on compression and ejection normal stresses. Laser surface texturing extended the MoS2 lubricant service life by approximately 2 to 50 times compared with non-textured surfaces, depending on TD and configuration. Increasing TD consistently enhanced lubricant lifespan. Among all configurations, the pin-and-disc system exhibited the longest service life, while the textured pin configuration showed the shortest. Finite element results identified ejection stress as the dominant factor governing lubricant depletion, providing new insight into stress-mediated solid lubrication mechanisms for 6082-T6 aluminium alloy.
