Table 1.

Examples for leaf-inspired technical applications as based on functional elements which were considered in this review. The remark “unknown *” indicates evidence for still unknown functions.

Leaf Structure/Trait	Biological Function/Task	Biomimetic Application	References
Leaf shape and size	Heat transfer, self-shading, competition, unknown *	Heat transfer (cooling of buildings and solar panels)	[30,31,32]
Stomata	Regulated gas exchange	Evaporative cooling, drug delivery, particle micromanipulation, microfluidic pump or valve, breathable fabrics, water harvesting, smart membranes	[58,59,60,62,63,64,65]
Epidermis and trichomes	Various protective functions (e.g., evaporation, herbivores, pathogens, irradiation, heat), water capture, water absorption, climbing, channeling of light, mechanical stabilization, unknown *	Capillary water conduction, drag reduction, antifouling, insect control, fog harvesting, valve concepts, adhesion and climbing for robotics, light reflectance, light capture	[123,124,125,126,127,128,129,130,131,132,133,134,135,136]
Mesophyll	Photosynthesis, mechanical stabilization by turgor, light conduction, various metabolic processes, water storage (in leaf succulents), leaf movements	Electricity generation, photoreduction, photocatalysis, water transport, actuator concepts	[161,162,163,164,165,166,167,168]
Venation	Supply and distribution of water, export of assimilates, mechanical stabilization	Transport in networks, microfluidics, heat exchange, mechanical stabilization	[179,185,186,187,188,189,190,191,192,193,194,195]