Bat-El PinchasikTel Aviv University | TAU · School of Mechanical Engineering
Bat-El Pinchasik
PhD
About
45
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Introduction
Skills and Expertise
Publications
Publications (45)
The Zener diode (Z-diode) is often used as a voltage regulator, and is designed to operate in reverse breakdown. Namely, it can conduct current in the reverse direction when a certain voltage, known as the Zener voltage, is applied. Analogous to electric diodes, liquid diodes are microscale surface structures that promote spontaneous unidirectional...
Adult female desert locusts (Schistocerca gregaria) dig underground to lay their eggs, ensuring optimal conditions for successful hatching. Digging is performed using the two pairs of oviposition valves at the tip of the female's abdomen. These valves are subjected to considerable shear forces during the repeated digging cycles, potentially leading...
Insects flap their wings through a highly specialized musculoskeletal system that allows the wings to rotate about three degrees of freedom. Consequently, the wingtip trajectory is adjustable in 3D, and accompanied with appropriate wing feathering (wing pitch). Remarkably, the complex flapping motion is achieved by thoracic muscles acting on the wi...
Background
The female locust is equipped with unique digging tools, namely two pairs of valves—a dorsal and a ventral—utilized for excavating an underground hole in which she lays her eggs. This apparatus ensures that the eggs are protected from potential predators and provides optimal conditions for successful hatching. The dorsal and the ventral...
Many organisms in nature use local interactions to generate global cooperative phenomena. To unravel how the behavior of individuals generates effective interactions within a group, we introduce a simple model, wherein each agent senses the presence of others nearby and changes its physical motion accordingly. This generates non-physical, or virtua...
Locusts are renowned for their coordinated locomotion, in which juveniles swarm and walk in a synchronized fashion. While it is generally accepted that vision is the main form of communication enabling this behavior, it is suggested here that mechanical vibrations may also contribute to communication within the group. Using a laser Doppler vibromet...
Miniature flapping drones can potentially operate in small spaces, using lightweight membranous wings. Designing these flexible wings appropriately is crucial for effective flight performance. 3D printing allows not only to fabricate high‐fidelity, insect‐inspired wings but also to further improve their design and shorten the development period for...
Liquid diodes are surface structures that facilitate the spontaneous flow of liquids in a specific direction. In nature, they are used to increase water collection and uptake, reproduction, and feeding. However, large networks with directional properties are exceptional and are typically limited up to a few centimeters. Here, we simulate, design, a...
Many organisms in nature use local interactions to generate global cooperative phenomena. To unravel how the behavior of individuals generates effective interactions within a group, we introduce a simple model, wherein each agent senses the presence of others nearby and changes its physical motion accordingly. This generates between agents interact...
Liquid diodes are surface structures that facilitate the flow of liquids in a specific direction. When these structures are within the capillary regime, they promote liquid transport without the need for external forces. In nature, they are used to increase water collection and uptake, reproduction, and feeding. While nature offers various one-dime...
Hypothesis:
Biphilic surfaces, namely surfaces comprising hydrophilic areas with a (super)hydrophobic background, are used in nature and engineering for controlled dropwise condensation and liquid transport. These, however, are highly dependent on the surface temperature and subcooling.
Experiments:
Here, biphilic surfaces were cooled inside a r...
Directional and self-propelled flow in open channels has a variety of applications, including microfluidic and medical devices, industrial filtration processes, fog-harvesting, and condensing apparatuses. Here, we present versatile three-dimensional-printed liquid diodes that enable spontaneous unidirectional flow over long distances for a wide ran...
Directional and self-propelled flow in open channels has a variety of applications, including microfluidic and medical devices, industrial filtration processes, fog-harvesting and condensing apparatuses. Here, we present versatile three-dimensional (3D)-printed liquid diodes that enable spontaneous unidirectional flow over long distances for a wide...
Robotic Swimmers The BackBot is an untethered miniature robot, inspired by diving insects commonly known as backswimmers. The Backbot regulates its buoyancy autonomously by tuning the volume of an external gas reservoir through controlled nucleation and release of microbubbles. It requires little energy to operate in comparison to traditional under...
The backswimmer is an aquatic insect, capable of regulating its buoyancy underwater. When it enters the water, it entraps an air bubble in a superhydrophobic hairy structure covering its abdomen. While this bubble is mainly used for respiration, it also functions as an external inflatable gas reservoir for buoyancy regulation. Namely, hemoglobin is...
The female locust has a unique mechanism for digging in order to deposit its eggs deep in the ground. It uses two pairs of sclerotized valves to displace the granular matter, while extending its abdomen as it propagates underground. This ensures optimal conditions for the eggs to incubate and provides them with protection from predators. Here, the...
Various insects can entrap and stabilize air plastrons and bubbles underwater. When these bubbles interact with surfaces underwater, they create air capillary bridges that de-wet surfaces and even allow underwater reversible adhesion. In this study, a robotic arm with interchangeable three-dimensional (3D)-printed bubble-stabilizing units is used t...
The female locust has a unique mechanism for digging in order to deposit its eggs deep in the ground. It utilizes two pairs of sclerotized valves to displace the granular matter, while extending its abdomen as it propagates underground. This ensures optimal conditions for the eggs to incubate, and provides them with protection from predators. Here,...
The backswimmer fly is an aquatic insect, capable of regulating its buoyancy underwater. Its abdomen is covered with hemoglobin cells, used to bind and release oxygen, reversibly. Upon entering water, the fly entraps an air bubble in a superhydrophobic hairy structure on its abdomen for respiration. This bubble, however, can change its volume throu...
The nature of adhesion of droplets to surfaces is a long pending scientific question. With the evolution of complex surfaces, quantification and prediction of these forces become intricate. Nevertheless, understanding these forces is highly relevant for explaining liquid transport in nature and establishing design guidelines for manmade interfaces....
Many insects can climb smooth surfaces using hairy adhesive pads on their legs mediated by tarsal fluid secretions. It was previously shown that a terrestrial beetle can even adhere and walk underwater. The naturally hydrophobic hairs trap an air bubble around the pads, allowing the hairs to make contact to the substrate like in air. However, it re...
Small animals, such as worms, snails, and insects use interfacial phenomena to propel and perform locomotion. These phenomena emerge at the liquid–air, solid–liquid, and liquid–liquid interfaces. With robots becoming smaller and lighter, interfacial phenomena become central in their design, and withhold potential solutions for adhesion, locomotion,...
In nature, surfaces are evolutionarily designed to allow adaptation of species to their environments. Insects make extensive use of interfacial phenomena because of their small size and thus, large surface-area-to-volume ratio. This enables them to walk on different terrains, dive, swim, and adhere to surfaces in air and underwater. Moreover, they...
When a supersaturated aqueous solution flows over a microstructured, hydrophobic surface, bubbles tend to nucleate. Here, we control heterogeneous nucleation of gas bubbles from supersaturated CO2 solution. By designing the shape, size, and arrangement of hydrophobic micropillars and by adjusting the flow we obtain uniform nucleation patterns. It i...
Microlens arrays are key elements for light management in optoelectronic devices. The recent advancement in the wearable intelligent electronics has driven the development of flexible microlenses. In this work, we show a controllable and scalable surface-droplet based strategy to create unconventional flexible polymer microlens arrays. The techniqu...
Superhydrophobic surfaces are usually assumed to be rigid so that liquids do not deform them. Here we analyze how the relation between microstructure and wetting changes when the surface is flexible. Therefore we deposited liquid drops on arrays of flexible micropillars. We imaged the drop's surface and the bending of micropillars with confocal mic...
Bubble-particle interaction is of great theoretical and practical importance in flotation. Significant progress has been achieved over the past years. E.g. the process of bubble-particle collision is reasonably well understood. This, however, is not the case for bubble-particle attachment leading to three-phase contact line formation due to the dif...
Constructing controllable liquid patterns with high resolution and accuracy is of great importance in droplet depositions for a range of applications, such as 3D printing of optical and electronic devices, bio-microarrays, and highly efficient chemical conversion in compartment. Simple surface chemical micropatterns are popularly used to regulate t...
Designing materials for water harvesting has gained much attention in recent years as water scarcity continues to be one of the biggest problems facing mankind. In this issue of ACS Nano, Xu et al. propose a new device for harvesting water from fog. They use conically shaped copper wires with periodic roughness to enhance condensation and transport...
Full reversibility between the Cassie and Wenzel superhydrophobic states through acoustic pressure is reported by Bat-El Pinchasik, Hidehiko Asanuma, and co-workers in article 1600722. Ultrasonication is used both for the nucleation of bubbles directly on superhydrophobic surfaces and oppositely for promoting the collapse of an entrapped air film t...
Full reversibility between the Cassie and Wenzel superhydrophobic states through acoustic pressure is reported: ultrasonication is used both for the nucleation of bubbles directly on superhydrophobic surfaces and oppositely for promoting the collapse of an entrapped air film to reversibly manipulate the material surface properties and the interacti...
A new method of fabrication of calcium carbonate microparticles of ellipsoidal, rhomboidal and spherical geometries is reported by adjusting the relative concentration ratios of the initial salt solutions and/or the ethylene glycol content in the reaction medium. Morphology, porosity, crystallinity and loading capacity of synthesized CaCO3 template...
Exosome-like vesicles (ELVs) are a novel class of biomarkers that are receiving a lot of attention for the detection of cancer at an early stage. In this study the feasibility of using a surface enhanced Raman spectroscopy (SERS) based method to distinguish between ELVs derived from different cellular origins is evaluated. A gold nanoparticle based...
Controlled wetting and de-wetting of surfaces is a primary mechanism used by beetles in nature such as the lady bird and the leaf beetle for underwater locomotion. Their adhesion to surfaces underwater is enabled through the attachment of bubbles entrapped in their setae covered legs. Locomotion, however, is done by applying mechanical forces on th...
In this mini-review, assembly of anisotropic and Janus particles are described together with their diversified applications. Various classes of anisotropic and Janus particles are considered: liposomes and vesicles, polymeric capsules and particles, whose modification can be divided into: a) self-assembly, b) self-organization, wherein self-assembl...
Bubbles are widely used by animals in nature in order to fulfill important functions. They are used by animals in order to walk underwater or to stabilize themselves at the water/air interface. The main aim of this work is to imitate such phenomena, which is the essence of biomimetics. Here, bubbles are used to propel and to control the location of...
We have developed a nanoplasmonic-based approach to induce nanometer-sized local defects in the phospholipid membranes. Here, gold nanorods and nanoparticles having plasmon resonances in the nearinfrared (NIR) spectral range are used as optical absorption centers in the lipid membrane. Defects optically induced by NIR-laser irradiation of gold nano...
The group of silanes is one of the most abundant classes of molecules used for surface modification. In most studies, silanization is made from the vapor phase or solution. Here, an easy, robust, and fast way not only to modify, but also to map, control, and predict the wetting profiles on silicon surfaces after silanization and the final character...
Developing carriers comprised of biomaterials and capable of withstanding significant mechanical pressures, structural deformations and at the same time delivering biomolecules is of high interest for drug delivery. Using colloidal probe AFM combined with quantitative fluorescence microscopy, we investigated mechanical properties and release from C...
Nanoplasmonic biosensors based on gold nanoparticle functionalized smooth silica and porous calcium carbonate particles are presented. It is identified in this comparative study the role of porosity for adsorbing gold nanoparticles and subsequent detection of biomarkers. That is further applied in this study for detection of biomarkers. Detection o...
A prototype triple GEM detector has been constructed with an area of ̃2000 cm2, based on foils of 66 cm x 66 cm. GEMS of such dimensions have not been made before, and innova-tions to the existing technology were made to build this detector. A single-mask technique overcomes the cumbersome practice of alignment of two masks, which limits the achiev...