Zinc-catecholete frameworks biomimetically grown on marine polysaccharide microfibers for soft electronic platform

Integrating functional nanomaterials on nonplanar organisms has emerged as a rising technology,while significant mismatch would cause interface failure and poor durability.Herein,we demonstrate a facile strategy to assemble crystalline catecholate frameworks with honeycomb lattice on seaweed-derived polysaccharide microfibers,which is expected to form biomimetic connections and maintain durable stability.By physiological coagulation,well-aligned ZnO nanoarrays are tightly attached on alginate fibers,which is fractionally adopted as sacrifice for heteroepitaxial growth of zinc-catecholate frameworks(Zn3(HHTP)2).Benefiting from amplification effect of in-situ formed heterojunctions,promoted interfacial charge transfer is achieved,which allows for fabricating broadband photodetectors.Combined with high porosity for gas adsorption,the heteroepitaxial catecholate framework further enables its use as highly selective ppb-level triethylamine sensors.This work provides a promising strategy for heteroepitaxial growth of catecholate frameworks on organo-substrates and opens new applications in wearable sensor platform based on comfortable biofibers.

Shape preserving topology optimization for structural radar cross section control

The purpose of this paper is to present a shape preserving topology optimization method to prevent the adverse effects of the mechanical deformation on the Radar Cross Section(RCS).The optimization will suppress the variation of RCS on the perfect conductor surface by structural design.On the one hand,the physical optics method is utilized to calculate the structural RCS,which is based on the surface displacement field obtained from the finite element analysis of the structure.The corresponding design sensitivities of topology optimization are derived analytically and solved by the adjoint method.On the other hand,the RCS variation and mechanical performance are taken into account simultaneously by extending a standard compliance-based topology optimization model.Two optimization formulations are discussed in an illustrative example,where the influences of upper limits of the compliance and the RCS variation are considered.Two more examples are further tested to show the ability and validity of the proposed optimization method.

Interfacial energy barrier tuning of hierarchical Bi_(2)O_(3)/WO_(3) heterojunctions for advanced triethylamine sensor

Traditional triethylamine(TEA)sensors suffer from the drawback of serious cross-sensitivity due to the low charge-transfer ability of gas-sensing materials.Herein,an advanced anti-interference TEA sensor is designed by utilizing interfacial energy barriers of hierarchical Bi_(2)O_(3)/WO_(3) composite.Benefiting from abundant slit-like pores,desirable defect features,and amplification effect of heterojunctions,the sensor based on Bi_(2)O_(3)/WO_(3) composite with 40%Bi_(2)O_(3)(0.4-Bi_(2)O_(3)/WO_(3))demonstrates remarkable performance in terms of faster response/recovery time(1.7-fold/1.2-fold),higher response(2.1-fold),and lower power consumption(30℃-decrement)as compared with the pristine WO_(3) sensor.Furthermore,the composite sensor exhibits long-term stability,reproducibility,and negligible response towards interfering molecules,indicating the promising potential of Bi_(2)O_(3)/WO_(3) heterojunctions in anti-interference detection of low-concentration TEA in real applications.This work not only offers a rational solution to design advanced gas sensors by tuning the interfacial energy barriers of heterojunctions,but also provides a fundamental understanding of hierarchical Bi_(2)O_(3) structures in the gas-sensing field.

Defect promoted photothermoelectric effect in densely aligned ZnO nanorod arrays for self-powered position-sensitive photodetection

Sustainable light energy from ambient environment has attracted particular attention to meet the evergrowing need of small-scale electronics.The modulation of intercorrelated thermal and electronic transport is one of the crucial aspects for reliable photothermoelectric electronics.Herein,a defectpromoted photothermoelectric effect is demonstrated in densely aligned ZnO nanorod array with rich lattice defects.The defect-rich ZnO device delivers high electrical conductivity and large Seebeck coefficient to enable significant improvement of photothermoelectric energy conversion and self-powered photodetection.The position sensitivity reaches approximately 0.19 mV mm^(-1),and the temperature gradient induced electric field makes up for the suppression in the photothermoelectric process.The synergism between intrinsic defects and extra temperature field plays an important role in promoting the photothermoelectric properties of dense ZnO nanorod array.This study is interesting for interpreting the thermo-phototronic phenomena as well as demonstrating the possibility of defect engineering and phonon engineering to enable highly efficient light energy scavenging and self-powered photodetection.