Study of petal topography ofLysimachia arvensisgrown under natural conditions

Fabrication and friction characteristics of arbitrary biosurfaces

There are many different types of surfaces found in nature which can increase or reduce friction, such as the well-studied frog toe or lotus leaf. However, methods for replicating these surfaces on a large scale for use in industrial applications are needed in order to take advantage of this natural friction engineering. Most replication processes rely on molding that requires an input surface size comparable to the desired output surface. We present a novel approach of replicating large-scale biosurfaces using a laser scanning confocal microscope for surface digitization and 3D two-photon lithography for the fabrication of the digitized surface. Two different natural surfaces (banana skin and daffodil petal) were replicated. An intermediary tiling process was used to cover a target area of arbitrary size independent of the input texture size. The surfaces were coated with a thin layer of ZnO, and the frictional and wettability characteristics of the replicated surfaces were then examined, demonstrating significant friction reduction up to 42% and increased hydrophobicity due to the presence of texture.

Cellulose-Based Biomimetics and Their Applications

Nature has been producing cellulose since long before man walked the surface of the earth. Millions of years of natural design and testing have resulted in cellulose-based structures that are an inspiration for the production of synthetic materials based on cellulose with properties that can mimic natural designs, functions, and properties. Here, five sections describe cellulose-based materials with characteristics that are inspired by gratings that exist on the petals of the plants, structurally colored materials, helical filaments produced by plants, water-responsive materials in plants, and environmental stimuli-responsive tissues found in insects and plants. The synthetic cellulose-based materials described herein are in the form of fibers and films. Fascinating multifunctional materials are prepared from cellulose-based liquid crystals and from composite cellulosic materials that combine functionality with structural performance. Future and recent applications are outlined.