Table 6.

Results of various bioinspired designs exploited for the enhancement of cutting or machining tools, as reported in the literature.

Bioinspired Structure	Conclusions/Texture Effect
Sea urchin teeth-inspired rock-cutting tool (Crystalline calcite teeth/epoxy composite) [271,272]	Self-breaking or fracturing leads to self-sharpening. Detailed description of self-sharpening phenomena.
Dung beetle-inspired Bulldozing plate (UHMWPE) [267]	Bionic UHMWPE could reduce soil adhesion and draught considerably. 30% reduction in cutting resistance.
Lotus leaf/Shark skin-inspired soil shovel/tillage tool (Steel-based) [266]	1.85–4% reduction in cutting resistance.
Dung beetle-inspired toothed wheel tool (Steel-based) [35]	16.5% reduction in cutting resistance. 11.8% reduction in stress concentration. 24% increased microbasin.
Shark skin-inspired subsoiler tillage tool (Steel-based) [303]	21.9% reduction in cutting resistance. 24.8% reduction in consumption energy. Improved crop stress resistance.
Mole pelt-inspired cutting blade for tillage tool (Steel-based) [36,282]	12.8% reduction in cutting resistance. 4% reduction in torque. 60% improved stubble breaking rate.
Pangolin-inspired drill bit for dry rock cutting (Impregnated diamond bit) [260]	97.5% increased drilling speed. 26.8% increased service life.
Mole claw-inspired drill bit (Impregnated diamond bit) [264]	230% increased drilling efficiency. 345% increased service life.
Beetle/Earthworm-inspired drill bit (Impregnated diamond bit) [191,261]	91% increased wear resistance. 27% increased grinding performance.
Bamboo/human tooth/annual ring/shell/mole pelt-inspired drill bit (Impregnated diamond bit) [285]	Improved cutting resistance. Improved wear resistance. 250% increased penetration rate.
Cat claw-inspired drill bit (Impregnated diamond bit) [304]	13% increased penetration rate.
Dung beetle-inspired drill bit (cemented carbide bit) [41]	45% increased drilling speed. 23% decreased wear rate.
Dung beetle-inspired microgrooves/pits turning tool for dry cutting (AISI 1045 steel) [305]	24% decreased cutting force. 29% decreased cutting temperature. Grooves and pits led to wear debris (graphite) storage and improved lubrication.
Dung beetle-inspired microgrooved tool for dry machining of Ti-alloy (PCD tools) byFiber lasers [278]	Reduced friction coefficient. Reduced tool-chip contact length. Reduced cutting force. Reduced adhesion.
Rat claw-inspired microdimples/grooves for dry cutting of Ti-alloy (cemented carbide tool) [296]	Increased tool’s anti-adhesion ability. Increased chip-breaking efficiency. Increased chip curling.
Snakeskin-inspired tool for dry cutting of AISI/SAE 4140 (cemented carbide inserts) byFemto second lasers [294]	65% reduced cutting temperature. 51% reduced cutting power. 16% reduced cutting force. Reduced sticking sliding contact.
Sea urchin/Shark teeth-inspired microtexture/serrated cutting edges for finish turning of ferrous alloys. (PCBN inserts) [44]	Reduced tool wear. Reduced finished surface roughness, Ra.
Corn leaf’s teeth-inspired microgrooved blade for milling of Al-alloy byFEM simulation [289]	10% reduced cutting force. Reduced cutting temperature. Reduced cutting vibration.
Beetle-inspired microtexture on tool cutter for milling of Ti-alloy (PCD and carbide tool) [306]	7% reduced cutting stress. Reduced cutting force. Reduced tool wear. Reduced cutting force fluctuation.
Badger teeth-inspired microdimples/grooves on circular saw blade (Steel-based tool) [307]	Reduced cutting torque. Reduced workpiece tension. Increased cutting quality.
Shark skin-inspired microgrooves on cutting tool with WS2/C coating (Carbide tool) [298]	Reduced flank wear. Reduced surface roughness. Reduced surface temperature.
Desert scorpion-inspired microgrooves on cutting tool (Carbide tool) [299]	Reduced flank wear. No effect on surface roughness. Textures on the flank faces could also act as storage for powder chip and can protect the surface from abrasion.
Scorpion or dung beetle-inspired microgrooves or dimples on cutting tool (Carbide tool) byLaser processing [293]	4.2% reduction in friction in dry cutting condition. 5.1% reduction in friction in oil lubrication. Superior chip flow in groove microtexture perpendicular. Groove microtexture can store lubrication oil and improve lubrication and cooling effect during cutting.