Cross-Species Bioinspired Anisotropic Surfaces for Active Droplet Transportation Driven by Unidirectional Microcolumn Waves.

Natural evolution has endowed diverse species with distinct geometric micro/nanostructures exhibiting admirable functions. Examples include anisotropic microgrooves/microstripes on the rice leaf surface for passive liquid directional rolling, and motile microcilia widely existed in mammals' body for active matter transportation through in situ oscillation. Till now, bionic studies have been extensively performed by imitating a single specific biologic functional system. However, bionic fabrication of devices integrating multispecies architectures is rarely reported, which may sparkle more fascinating functionalities beyond natural findings. Here, a cross-species design strategy is adopted by combining the anisotropic wettability of the rice leaf surface and the directional transportation characteristics of motile cilia. High-aspect-ratio magnetically responsive microcolumn array (HAR-MRMA) is prepared for active droplet transportation. It is found that just like the motile microcilia, the unidirectional waves are formed by the real-time reconstruction of the microcolumn array under the moving magnetic field, enabling droplet (1-6 µL) to transport along the predetermined anisotropic orbit. Meanwhile, on-demand droplet horizontal transportation on the inclined plane can be realized by the rice leaf-like anisotropic surface, showcasing active nongravity-driven droplet transportation capability of the HAR-MRMA. The directional lossless transportation of droplet holds great potential in the fields of microfluidics, chemical microreaction, and intelligent droplet control system.

[Study on Extraction Methods of Characteristic Wavelength of Visible Near Infrared Spectroscopy Used for Sugar Content of Hetao Muskmelon].

Hetao muskmelon is a unique fruit in the hetao area of northwest china, which has been loved by consumers. Sugar content is the important indicator of measuring the quality and mature of muskmelons. This research uses Maya 2000 pro portable spectrometer and PR-101α portable digital refractometer to get spectrum and sugar content values of "jinhongbao" muskmelon, researches the effect of different extraction methods of characteristic wavelength (stepwise multiple linear regression (SMLR), interval partial least squares(iPLS), backward interval partial least squares (biPLS) and synergy interval partial least squares (siPLS)) on model accuracy and prediction results. The results show: using biPLS method on extraction of characteristic wavelength will the full spectrum evenly divided into 20 subintervals, the PLS factors of 14, when removing 8 subintervals, and choosing the wavelength variable numbers of 218, getting the biPLS model is best, RMSE of corresponding calibration and prediction models is 0.9961 and 1.18. So using the biPLS method of extraction on spectrum wavelength could extract effectively the characteristic wavelengths of melon sugar content, increase the ability of model prediction, and achieve rapid detecting of sugar content about muskmelons.