Fast prototype and rapid construction of three-dimensional and multi-scaled pitcher for controlled drainage by systematic biomimicry

Biomimetic materials that use natural wisdom to solve practical problems are developing rapidly.The trend for systematic biomimicry is towards in-situ characterization of naturalcreatures with high spatial resolutions.Furthermore,rapid reconstruction of digital twin models with the same complex features as the prototype is indispensable.However,it faces bottlenecks and limits in fast characterization and fabrication,precise parameter optimization,geometricdeviations control,and quality prediction.To solve these challenges,here,we demonstrate astate-of-the-art method taking advantage of micro-computed tomography and three-dimensional printing for the fast characterization of the pitcher plant Nepenthes x ventrata and fabrication of its biomimetic model to obtain a superior drainage controller with multiscale structures withprecise surface morphology optimization and geometric deviation control.Thefilm-rupture-based drainage dynamic and mechanisms are characterized by x-ray and high-speed videography,which determines the crucial structures for unique directionaldrainage.Then the optimized artificial pitchers are further developed into sustained drainage devices with novel applications,such as detection,reaction,and smoke control.

3D打印过程中液体可控输送的研究进展及展望

随着信息技术的快速发展,3D打印实现了由数字化模型到三维实物的快速转化。目前,3D打印已广泛用于复杂精细三维结构和定制化结构的制备,尤其是在仿生学研究中极大促进了仿生微流体的发展。从界面材料物理化学的角度看,3D打印实质是打印材料输送与固-液相变过程。然而,沉积、固化、黏附等界面科学问题限制着其效率的提高。解决这些界面问题将大幅缩短打印时间,提高打印分辨率、材料利用率和打印件质量。针对目前在3D打印中所遇到的界面科学问题,文中系统概述了多种3D打印技术的基本原理及相应界面问题,并展望其解决方法,最后简要介绍了3D打印在仿生液体输送领域的最新发展和应用。

Bionic microchannels for step lifting transpiration

Those various cross-sectional vessels in trees transfer water to as high as 100 meters,but the traditional fabrication methods limit the manufacturing of those vessels,resulting in the non-availability of those bionic microchannels.Herein,we fabricate those bionic microchannels with various cross-sections by employing projection micro-stereolithography(PμSL)based 3D printing technique.The circumradius of bionic microchannels(pentagonal,square,triangle,and five-pointed star)can be as small as 100μm with precisely fabricated sharp corners.What's more,those bionic microchannels demonstrate marvelous microfluidic performance with strong precursor effects enabled by their sharp corners.Most significantly,those special properties of our bionic microchannels enable them outstanding step lifting performance to transport water to tens of millimeters,though the water can only be transported to at most 20 mm for a single bionic microchannel.The mimicked transpiration based on the step lifting of water from bionic microchannels is also achieved.Those precisely fabricated,low-cost,various cross-sectional bionic microchannels promise applications as microfluidic chips,long-distance unpowered water transportation,step lifting,mimicked transpiration,and so on.

Bioinspired Stable Single‑Layer Janus Fabric with Directional Water/Moisture Transport Property for Integrated Personal Cooling Management

Extensive progress has been achieved regarding Janus fabric for directional water transport due to its excellent and feasible personal cooling management ability,which has great significance for energy conservation,pollution reduction,and human health.However,existing Janus asymmetric multilayer fabrics for directional water transport are still limited by their com-plicated syntheses and poor stabilities.Inspired by the compositionally graded architecture of leaf cuticles,we propose a single-layer Janus personal cooling management fabric(JPCMF)via a one-step electrospinning method.The JPCMF shows not only great directional bulk water transport ability but also asymmetry moisture(water vapor)transport ability with a high asymmetry factor(1.49),water vapor transmission value(18.5 kg^(-1) m-2 D-1),and water evaporation rate(0.735 g h^(-1)).Importantly,the JPCMF exhibits outstanding durability and stability thanks to a novel electrostatic adsorption-assisted self-adhesion strategy for resisting abrasion,peeling and pulling.With these characteristics,the JPCMF can achieve a 4.0°C personal cooling management effect,better than taht of cotton fabric,on wet skin.The good biocompatibility and nontoxic-ity also endow the JPCMF with the potential to be a self-pumping dressing.Our strategy should facilitate a new method for developing next-generation intelligent multifunctional fabrics.

Edge effect of optical surfacing process with different data extension algorithms

This study presents a strategy which integrates extra polishing path （EPP） and error map extension to weaken the edge effect in the ultraprecise optical surfacing process. Different data extension algorithms were pre- sented and analyzed. The neighbor-hood average can be selected as the frequently-used method, as it has not bad precision and time-saving performance for most surface forms through the simulation results and practical experi- ment. The final error map was obtained, its peak-to-valley （PV） was 0.2732 and root mean square （RMS） was 0.0282 （2 = 632.8nm）. The edge effect was weakened and suppressed well through the experiment.

Error compensation for three-dimensional profile measurement system

Three-dimensional （3D） profile measurement is an indispensable process for assisting the manufacture of various optic, especially aspheric surfaces. This work presents the measurement error calibration of a 3D profile measurement system, namely PMI700. Measurement errors induced by measuring tool radius, alignment error and the temperature variation were analyzed through geometry analysis and simulation. A quantitative method for the compensation of tool radius and an alignment error compensation model based on the least square method were proposed to reduce the measurement error. To verify the feasibility of PMI700, a plane and a non-uniform hyperboloidal mirror were measured by PMI700 and interferometer, respectively. The data provided by two systems were high coincident. The direct subtractions of results from two systems indicate RMS deviations for both segments were less than 0.22.

Biomimetic directional transport for sustainable liquid usage

Through hundreds of millions of evolution,animals and plants have possessed their unique structures to adapt to natural variations.As a familiar process,liquid transportation plays an important part in both production and life,and researchers focus on how to achieve this process in a convenient and efficient way without energy input.Inspired by nature,various bioinspired structures are reported and have won multiple achievements.This review starts from basic theory about surface wettability,and then summarises the creatures with special liquid transport functions as well as crucial structures that cause this phenomenon.Next,the recent articles about transporting liquid by bioinspired materials are introduced.Finally,we proposed a brief conclusion and the prospect of bionic materials in the future.

New conceptual microfluidics technology:light manipulation of liquid slugs in liquid crystal polymer microactuators

Microsystems that manipulate small amounts of fluids to transport in a pre-defined direction and to perform reactions or analyses are quite important in both laboratory investigations and industry applications[1],due to their close relevance to people’s daily life and commercial run.Natural creatures,after centuries’evolution,have realized the importance of structure and wettability designs in achiev-