3D-printed cellular tips for tuning fork atomic force microscopy in shear mode

Conventional atomic force microscopy (AFM) tips have remained largely unchanged in nanomachining processes, constituent materials, and microstructural constructions for decades, which limits the measurement performance based on force-sensing feedbacks. In order to save the scanning images from distortions due to excessive mechanical interactions in the intermittent shear-mode contact between scanning tips and sample, we propose the application of controlled microstructural architectured material to construct AFM tips by exploiting material-related energy-absorbing behavior in response to the tip–sample impact, leading to visual promotions of imaging quality. Evidenced by numerical analysis of compressive responses and practical scanning tests on various samples, the essential scanning functionality and the unique contribution of the cellular buffer layer to imaging optimization are strongly proved. This approach opens new avenues towards the specific applications of cellular solids in the energy-absorption field and sheds light on novel AFM studies based on 3D-printed tips possessing exotic properties.

Preparation of BTO@GO@PU Composite Membrane and its Application in Microwave Absorption Field

Barium titanate/graphene oxide/polyurethane (BTO@GO@PU) composite membranes for microwave absorption were designed and fabricated by mechanical-blending of BTO and GO in PU medium, followed by mold formation. The cross section morphology of the BTO@GO@PU membrane indicated that the BTO nanoparticles with 450 nm average diameter are successfully incorporated into the PU matrix. Mechanical tensile measurement showed that, as the amount of BTO nanoparticles increased from 5 wt% to 20 wt%, the elastic modulus of the corresponding membrane increased up to 23.0 MPa elongation with the elongation above 450 %. Microwave absorption property of the BTO@GO@PU membranes were evaluated by measuring its reflection loss in the frequency range of 0.1-18 GHz. With the addition of BTO up to 20 wt%, the maximum absorptivity of the composite reached up to 51 %. This is attributed to the dielectric loss of BTO nanoparticles.

Penerapan Model Horton Untuk Kuantifikasi Laju Infiltrasi

[ID] Kapasitas infiltrasi akan semakin menurun bila bidang resapan air semakin berkurang. Dampaknya limpasan air hujan yang menjadi aliran permukaan akan semakin meningkat. Konsep perencanaan yang memperbesar air hujan meresap ke dalam tanah akan mampu mengurangi aliran permukaan. Penelitian ini bertujuan untuk kuantifikasi laju infiltrasi air hujan dengan menerapkan model Horton. Metode yang dilakukan adalah uji sampel di lapangan terhadap laju infiltrasi pada bidang tanah yang tidak ada lubang resapan dan bidang tanah yang diberi lubang resapan. Dimensi lubang resapan adalah diameter (Ø) 3 inchi, 4 inchi, dan 8 inchi dengan kedalaman 1,1 m menggunakan alat ukur double ring infiltrometer. Metode perhitungan menggunakan rumus infiltrasi Horton. Dapat disimpulkan bahwa lubang resapan berpengaruh terhadap peningkatkan laju infiltrasi air hujan ke dalam tanah, sehingga dapat meningkatkan daya resap air ke tanah. Laju infitrasi model Horton pada lubang resapan Ø 3 inchi, Ø 4 inchi, Ø 8 inchi dan tanpa lubang resapan adalah f (t) = 0,55+0,45e-14t ; f (t) = 0,4+1,5e-19,5 t ; f (t) = 2,3+1,8e-46t ; dan f (t) = 0,28+0,72e-10,7t. Nilai laju infiltrasi yang paling besar hingga paling kecil adalah f (0) = 4,1 m/jam (pada Ø 8 inchi); f (0) = 1,9 m/jam (pada Ø 4 inchi); f (0) = 1 m/jam (pada Ø 3 inchi); dan f (0) = 1 m/jam (tanpa lubang resapan). Perbandingan akumulasi waktu laju infiltrasi terhadap lubang resapan Ø 8 inchi adalah 3,8 kali lebih lambat (pada Ø 3 inchi), 3,6 kali lebih lambat (pada Ø 4 inchi), dan 6,63 kali lebih lambat (tanpa lubang resapan). [EN] Infiltration capacity will decrease if the water absorption field decreases. The impact of rainwater runoff which becomes surface runoff will increase. The concept of planning that enlarges rainwater seeps into the ground will be able to reduce surface flow. This study aims to quantify the rate of infiltration of rainwater by applying the Horton model. The method used is a sample test in the field against the infiltration rate in the field of land where there are no infiltration holes and soils are given infiltration holes. The dimensions of infiltration holes are diameter (Ø) 3 inches, 4 inches, and 8 inches with a depth of 1.1 m using a double ring infiltrometer measuring instrument. Calculation method using Horton infiltration formula. It can be concluded that infiltration holes affect the rate of infiltration of rainwater into the soil, so that it can increase the absorption rate of water to the ground. Inflation rate of Horton model in infiltration hole Ø 3 inches, Ø 4 inches, Ø 8 inches and without infiltration hole is f (t) = 0.55 + 0.45e-14t; f (t) = 0.4 + 1.5e-19.5 t; f (t) = 2.3 + 1.8e-46t; and f (t) = 0.28 + 0.72e-10.7t. The value of the largest infiltration rate to the smallest is f (0) = 4.1 m / hour (at Ø 8 inches); f (0) = 1.9 m / hour (at Ø 4 inches); f (0) = 1 m / hour (at Ø 3 inches); and f (0) = 1 m / hour (without infiltration holes). Comparison of accumulated infiltration time to infiltration hole Ø 8 inches is 3.8 times slower (at Ø 3 inches), 3.6 times slower (at Ø 4 inches), and 6.63 times slower (without infiltration holes).

Synthesis and properties of novel UV – curable hyperbranched waterborne polyurethane/Fe3O4 nanocomposite films with excellent magnetic properties

A novel magnetic WPU/Fe3O4 nanocomposite has been successfully synthesized by in situ polymerization method. The nanocomposite films present excellent magnetic properties, which would have a promising application in microwave-absorption field.

Application of Parallel Mechanism in Multi-DIM Vibration Absorbers

It introduces ways and means of designing this kind of vibration absorbers which are presented using parallel mechanisms as the main mechanisms ,it ,which takes the parallel mechanisms with 3-DOF translation as an example, validates the feasibility of the method, and enumerates some of the parallel mechanisms that are fit for multi-DIM vibration absorber. In a word, the multi-DIM vibration absorber system based on parallel mechanism is a new idea and breakthrough in multi-DIM vibration absorption field, which has the characteristic of simple structure, compact mechanism, high accuracy, partially or fully decoupled mechanism easy for control and so on, and provides a new method for the study of Multi-DIM vibration.