Artificial stimuli-responsive surfaces that can mimic the dynamic function of living systems have attracted much attention. However, there exist few artificial systems capable of responding to dual- or multistimulation as the natural system does. Herein, we synthesize a pH and glucose dual-responsive surface by grafting poly(acrylamidophenylboronic acid) (polyAAPBA) brush from aligned silicon nanowire (SiNW) array. The as-prepared surface can reversibly capture and release targeted cancer cells by precisely controlling pH and glucose concentration, exhibiting dual-responsive AND logic. In the presence of 70 mM glucose, the surface is pH responsive, which can vary from a cell-adhesive state to a cell-repulsive state by changing the pH from 6.8 to 7.8. While keeping the pH at 7.8, the surface becomes glucose responsive--capturing cells in the absence of glucose and releasing cells by adding 70 mM glucose. Through simultaneously changing the pH and glucose concentration from pH 6.8/0 mM glucose to pH 7.8/70 mM glucose, the surface is dual responsive with the capability to switch between cell capture and release for at least 5 cycles. The cell capture and release process on this dual-responsive surface is noninvasive with cell viability higher than 95%. Moreover, topographical interaction between the aligned SiNW array and cell protrusions greatly amplifies the responsiveness and accelerates the response rate of the dual-responsive surface between cell capture and release. The responsive mechanism of the dual-responsive surface is systematically studied using a quartz crystal microbalance, which shows that the competitive binding between polyAAPBA/sialic acid and polyAAPBA/glucose contributes to the dual response. Such dual-responsive surface can significantly impact biomedical and biological applications including cell-based diagnostics, in vivo drug delivery, etc.

Capture and release of cancer cells: a thermoresponsive nanostructured surface is designed to reversibly capture and release cancer cells, wherein hydrophobic interaction helps the realization of target capture/release of cancer cells. The unique nature of the designed platform is based on the synergistic effect of hydrophobic interactions between the smart surface and the hydrophobic anchor (i.e., biotin‐BSA), and topographic interactions between the nanostructured substrates and cancer cells.

Unique underwater low adhesive superoleophobicity is discovered on the pallium-covered region of a short clam's shell. This property originates from the shell's inorganic composition of CaCO(3) and surface micro/nano-hierarchical structures. The oil-repellent shell provides an innovative strategy to develop novel underwater superoleophobic coatings using inorganic oxides such as copper oxide. This kind of coating is anticipated to be applied on engineering metals to protect aquatic equipment from oil contamination.

Compression, tension and high-velocity plate impact experiments were performed on a typical tough Zr 41.2 Ti 13.8 Cu 10 Ni 12.5 Be 22.5 (Vit 1) bulk metallic glass (BMG) over a wide range of strain rates from $10 À4 to 10 6 s À1 . Surprisingly, fine dimples and periodic corrugations on a nanoscale were also observed on dynamic mode I fracture surfaces of this tough Vit 1. Taking a broad overview of the fracture patterning of specimens, we proposed a criterion to assess whether the fracture of BMGs is essentially brittle or plastic. If the curvature radius of the crack tip is greater than the critical wavelength of meniscus instability [F. Spaepen, Acta Metall. 23 615 (1975); A.S. Argon and M. Salama, Mater. Sci. Eng. 23 219 (1976)], microscale vein patterns and nanoscale dimples appear on crack surfaces. However, in the opposite case, the local quasi-cleavage/separation through local atomic clusters with local softening in the background ahead of the crack tip dominates, producing nanoscale periodic corrugations. At the atomic cluster level, energy dissipation in fracture of BMGs is, therefore, determined by two competing elementary processes, viz. conventional shear transformation zones (STZs) and envisioned tension transformation zones (TTZs) ahead of the crack tip. Finally, the mechanism for the formation of nanoscale periodic corrugation is quantitatively discussed by applying the present energy dissipation mechanism.

The separation of oil–water mixtures in highly acidic, alkaline, and salty environment remains a great challenge. Simple, low‐cost, efficient, eco‐friendly, and easily scale‐up processes for the fabrication of novel materials to effective oil–water separation in highly acidic, alkaline, and salty environment, are urgently desired. Here, a facile approach is reported for the fabrication of stable hydrogel‐coated filter paper which not only can separate oil–water mixture in highly acidic, alkaline, and salty environment, but also separate surfactant‐stabilized emulsion. The hydrogel‐coated filter paper is fabricated by smartly crosslinking filter paper with hydrophilic polyvinyl alcohol through a simple aldol condensation reaction with glutaraldehyde as a crosslinker. The resultant multiple crosslinked networks enable the hydrogel‐coated filter paper to tolerate high acid, alkali, and salt up to 8 m H2SO4, 10 m NaOH, and saturated NaCl. It is shown that the hydrogel‐coated filter paper can separate oil–water mixtures in highly acidic, alkaline, and salty environment and oil‐in‐water emulsion environment, with high separation efficiency (>99%).

Topographic recognition of cancer cells is triggered by fractal gold nanostructures (FAuNSs), leading to dramatically enhanced recognition capability and efficient release of cancer cells with little damage. The unique characteristic of FAuNSs is the similar fractal dimension of their surface and that of a cancer cell. The design of fractal nanostructures will open up opportunities for functional design of bio-interfaces for highly efficient recognition and release of disease-related rare cells, which will improve detection in a clinical environment.

In nature, many organisms are able to accommodate a complex living environment by developing biological wet adhesive surfaces with unique functions such as fixation and predation. Significantly, most of these outstanding functions originate from the specialized micro/nanostructures and/or chemical components of these natural organisms. To design artificial surfaces with remarkable wet adhesive properties, the underlying mechanisms of the fascinating adhesion phenomena are further explored and summarized to provide continuous inspiration. Herein, a systematic overview of biological wet adhesive surfaces and the corresponding artificial counterparts from the perspective of surface micro/nanostructures is provided. First, the research progress of the typical biological wet adhesive surfaces such as the octopus, tree frogs, and mayfly larvae is introduced. Then, the fundamental models of surface adhesion in natural organisms and the commonly used instruments for measuring adhesion force are discussed. Later, the corresponding artificial wet adhesive surfaces inspired by these representative organisms are highlighted. After that, the typical methods for fabricating these surfaces are briefly introduced. Finally, future challenges and opportunities to develop bioinspired multiscaled wet adhesive surfaces with controlled adhesion are presented.

Periodic micro-grooved organogel surfaces can easily realize the anisotropic sliding of water droplets attributing to the formed slippery water/oil/solid interface. Different from the existing anisotropic surfaces, this novel surface provides a versatile candidate for the anisotropic sliding of water droplets and might present a promising way for the easy manipulation of liquid droplets for water collection, liquid-directional transportation, and microfluidics.