Liquid Drop Runs Upward between Two Nonparallel Plates

We have recently observed an interesting phenomenon: even under gravity, a microliter-scaled silicone oil drop was still able to run upward between two nonparallel plates that were approximately vertically placed. We also saw the same phenomenon in the case of isopropyl alcohol (IPA) drops. In this work, we developed simple models to interpret this phenomenon, followed by experimental validation. We demonstrated that, by changing the locations of drops or tilt and opening angles of plates, the moving directions of silicone oil, IPA, and water drops could be controlled. In the cases of silicone oil and IPA, we also found that the speed of a drop had a linear relation with the square of the drop location when the drop was far away from the corner of two nonparallel plates and that the drop moved faster as it became closer to this corner

Liquid Drop Runs Upward between Two Nonparallel Plates

We have recently observed an interesting phenomenon: even under gravity, a microliter-scaled silicone oil drop was still able to run upward between two nonparallel plates that were approximately vertically placed. We also saw the same phenomenon in the case of isopropyl alcohol (IPA) drops. In this work, we developed simple models to interpret this phenomenon, followed by experimental validation. We demonstrated that, by changing the locations of drops or tilt and opening angles of plates, the moving directions of silicone oil, IPA, and water drops could be controlled. In the cases of silicone oil and IPA, we also found that the speed of a drop had a linear relation with the square of the drop location when the drop was far away from the corner of two nonparallel plates and that the drop moved faster as it became closer to this corner

Bioinspired Plate-Based Fog Collectors

In a recent work, we explored the feeding mechanism of a shorebird to transport liquid drops by repeatedly opening and closing its beak. In this work, we apply the corresponding results to develop a new artificial fog collector. The collector includes two nonparallel plates. It has three advantages in comparison with existing artificial collectors: (i) easy fabrication, (ii) simple design to scale up, and (iii) active transport of condensed water drops. Two collectors have been built. A small one with dimensions of 4.2 × 2.1 × 0.05 cm³ (length × width × thickness) was first built and tested to examine (i) the time evolution of condensed drop sizes and (ii) the collection processes and efficiencies on the glass, SiO₂, and SU-8 plates. Under similar experimental conditions, the amount of water collected per unit area on the small collector is about 9.0, 4.7, and 3.7 times, respectively, as much as the ones reported for beetles, grasses, and metal wires, and the total amount of water collected is around 33, 18, and 15 times. On the basis of the understanding gained from the tests on the small collector, a large collector with dimensions of 26 × 10 × 0.2 cm³ was further built and tested, which was capable of collecting 15.8 mL of water during a period of 36 min. The amount of water collected, when it is scaled from 36 to 120 min, is about 878, 479, or 405 times more than what was collected by individual beetles, grasses, or metal wires

Bioinspired Plate-Based Fog Collectors

In a recent work, we explored the feeding mechanism of a shorebird to transport liquid drops by repeatedly opening and closing its beak. In this work, we apply the corresponding results to develop a new artificial fog collector. The collector includes two nonparallel plates. It has three advantages in comparison with existing artificial collectors: (i) easy fabrication, (ii) simple design to scale up, and (iii) active transport of condensed water drops. Two collectors have been built. A small one with dimensions of 4.2 × 2.1 × 0.05 cm³ (length × width × thickness) was first built and tested to examine (i) the time evolution of condensed drop sizes and (ii) the collection processes and efficiencies on the glass, SiO₂, and SU-8 plates. Under similar experimental conditions, the amount of water collected per unit area on the small collector is about 9.0, 4.7, and 3.7 times, respectively, as much as the ones reported for beetles, grasses, and metal wires, and the total amount of water collected is around 33, 18, and 15 times. On the basis of the understanding gained from the tests on the small collector, a large collector with dimensions of 26 × 10 × 0.2 cm³ was further built and tested, which was capable of collecting 15.8 mL of water during a period of 36 min. The amount of water collected, when it is scaled from 36 to 120 min, is about 878, 479, or 405 times more than what was collected by individual beetles, grasses, or metal wires

Separation of Oil from a Water/Oil Mixed Drop Using Two Nonparallel Plates

In this work, we have developed a simple approach to separate oil from a microliter-scaled water/oil mixture by squeezing the mixture using two nonparallel plates. Three pairs of plates with Teflon, SU-8, and SiO₂ coatings, respectively, are used in the tests, and all of these plates are capable of separating the water/oil mixed drops. 95.5% silicone oil and 97.0% light mineral oil have been collected from their corresponding mixtures with water through the pair of Teflon plates. Furthermore, on the basis of pressure difference inside a liquid drop, theoretical models have been developed to interpret the corresponding mechanisms of the separation process, as well as the observed phenomena. To judge whether two immiscible liquids could be separated using the developed approach, a sufficient condition has also been derived, which includes three theoretical relations. The sufficient condition is subsequently validated by experiments. This condition also provides criteria for choosing a good plate coating. Such a coating should ensure (i) the oil wets the plate surface with a relatively large contact angle, and has small contact angle hysteresis, and (ii) the advancing contact angle that the water/oil interface forms on the plate surface is larger than 90°

Behavior of a Liquid Drop between Two Nonparallel Plates

Liquid drops have shown interesting behaviors between two nonparallel plates. These plates may be fixed or movable relative to each other. In this work, we also explore these behaviors through a combination of theoretical and experimental investigations and obtain some new results. We show that when the two plates are fixed, different from the previous understanding, a lyophilic drop may not necessarily fill the corner of the two plates. We also demonstrate that it may fill the corner, when more liquid is added to the drop or when the top plate is lifted. Furthermore, we propose a physical model to interpret the shifting effect of a liquid drop. This effect appears when the drop is squeezed and relaxed between two nonparallel plates, and it has been used by some shorebirds to transport prey. On the basis of the proposed model, we have found three new phenomena related to the shifting effect

A Stable Intermediate Wetting State after a Water Drop Contacts the Bottom of a Microchannel or Is Placed on a Single Corner

It is considered that, after a water drop contacts the base of a roughness groove, water should immediately fill this roughness groove. Subsequently, Cassie–Baxter wetting state is transited to that of Wenzel. Accordingly, one of the criteria used to judge the transition from Cassie–Baxter to Wenzel states is whether a water drop has contact with the base of a roughness groove. In this work, through theoretical and experimental investigations, we show that this transition criterion does not always hold true in the case of microchannels. We first theoretically prove that, when an angle criterion is satisfied, there may exist an intermediate wetting state inside a microchannel after a water drop contacts the bottom of the microchannel. In this wetting state, water does not completely fill the microchannel, and air pockets still exist in its bottom corners. Also, the wetting state is stable in the sense that its energy state is lower than that of the Wenzel model. According to the angle criterion, such intermediate states may exist, for example, in microchannels with vertical sidewalls, when contact angles on the inner surfaces of these microchannels are larger than 135°. In addition to microchannels, the aforementioned intermediate state may also exist on a single corner (which is formed by a horizontal plate and an inclined plate), when the angle criterion is met. After theoretical modeling, we then conduct four types of tests on single corners and microchannels to validate the angle criterion. In these tests, once the angle criterion is met, stable intermediate states are observed on the corresponding samples. In addition, it is found from the two types of tests conducted on microchannels that, once Laplace pressure inside a water drop is gradually reduced, such an intermediate wetting state may be transited back to the original Cassie–Baxter state. On the other hand, the Wenzel state may not have such a reversal transition unless an additional force is applied to overcome energy barrier between Wenzel and Cassie–Baxter states

Behavior of a Liquid Drop between Two Nonparallel Plates

Liquid drops have shown interesting behaviors between two nonparallel plates. These plates may be fixed or movable relative to each other. In this work, we also explore these behaviors through a combination of theoretical and experimental investigations and obtain some new results. We show that when the two plates are fixed, different from the previous understanding, a lyophilic drop may not necessarily fill the corner of the two plates. We also demonstrate that it may fill the corner, when more liquid is added to the drop or when the top plate is lifted. Furthermore, we propose a physical model to interpret the shifting effect of a liquid drop. This effect appears when the drop is squeezed and relaxed between two nonparallel plates, and it has been used by some shorebirds to transport prey. On the basis of the proposed model, we have found three new phenomena related to the shifting effect

Recombinant Fragments of Antibodies

6. CoNct usloN The aim of the thesis was to establish, in the national conditions, technology of preparation of antibody reconrbinant fragrnents and to verífo the cornplete procedure using several model monoclonal antibodies with a potential diagnostic and therapeutic use. For tfuee antibodies' mAb TU-20, M75 and MEM97, recombinant |Ťagments in various formats (scFv fragments monovalent and bivalent, i.e. diabody, and intrabody for intracellular expression) were constructed and for their heterologous expression, vectors allowing expression in E. coli (as cytoplasmic inclusions, periplasmic inclusions and in soluble form) and in Drosophila 32 cells (expression of glycosylated forms of scFv fragments into the medium) were used. In case of proteins expressed in irrsoluble form, especially scFv F|1.2.32, renaturation procedures to obtain active scFv fragments were developed and optimized. The efnect of the length of the linker -(GlyrSer).- (where x is I to 4) connecting the variable domains of the light and heavy chain on the formation of different multimeric forms of scFv rvas studied. For obtaining solell monomeric scFv fragment, the length of 20 amino acid residues tumsd out optimal. Fragnrents rvith a linker l5 residues long. formed a mixture of monomers, dimers and trimers. the proportion of rvhich rvas..

Visualization 1: InstantScope: a low-cost whole slide imaging system with instant focal plane detection

Media 1 Originally published in Biomedical Optics Express on 01 September 2015 (boe-6-9-3210