Current state-of-the-art indoor positioning involves agent-carrying Global Positioning System (GPS) service. However, such system does not provide the needed sufficient accuracy. On the other hand, the Dynamic Vision Sensor (DVS) is becoming an attraction in the robotic perception field. This paper proposes a Visual Light Positioning (VLP) system architecture facilitated by a DVS and flickering LEDs at high frequencies for stationary and in-motion indoor Unmanned Vehicles (UVs). Besides, a pixel-level frequency-based filtering algorithm is developed for the given application. The high dynamic range and low latency of the DVS allows it to detect high frequency blinking and grants it high potential to be utilized in VLP systems. Since the DVS requires brightness change in the scene, flickering LEDs overcome this obstacle and allow continuous event generation even when the robotic agent is stationary.
Robotic vision has a major role in robotic manipulation in industry to assist and serve different applications. The traditional frame-based visual servoing has several limitations in visual feedback for robotic manipulation due to their operation method of capturing scenes continuously even if no changes in the scene is occurring. Alternatively, event cameras detects dynamic changes asynchronously at a high temporal resolution (1μs) with low latency and wide dynamic range hence, it is more of interest. In this project, I present visual sevoing method using event camera to achieve manipulation task. Additionally, to compensate for the inaccuracies and limitations of visual servoing, an event-driven tactile sensor is capable of fine manipulation with low-latency, less computational cost and power consumption. The event based visual servoing (EBVS) is validated experimentally using a commercial robot manipulator with an eye-in-hand configuration. The experiments proves the success of the EBVS method with a 100% success rate.
The onset of the COVID-19 pandemic necessitated wearing personal protective equipment (PPE) to prevent the spread of the SARS-CoV-2 virus. Amongst them, the wearing of face masks was recognized as one of the most crucial ways to reduce infection, as the mask works as filter for the different microorganisms. In this work the geometrical part of the filtration process of the N95 and surgical masks was studied using luminescent ultra-small silicon nanoparticles (Si-NPs) to represent the SARS-CoV-2 by spraying it on the mask using an atomizer. Scanning electron microscopy (SEM), and optical microscope were used to check the masks after depositing the Si-NPs. The obtained images show that the Si nanoparticles are trapped by the PE fiber network, indicating its ability to filter the SARS-CoV-2. This visualization using nanotechnology can help to further improve mask designs for better filtration.
Graphene oxide is one of the most interesting materials in research today due to its superior properties. In this study, different concentrations of graphene oxide (GO) were used to improve the hydrophilicity of the COC surface, thereby enhancing the wettability of its patterned microchannels. Argon-oxygen plasma was used to improve the adhesion between GO and COC surface. Plasma power of 30W with exposure times from 5min to 2hrs were carried out.
This work presents the exploration of the rare earth high entropy oxides based catalysts: 5%Ni-500/CeGdLaPrSmO-CP, 10%Ni-500/CeGdLaPrSmO-CP, 10%Ni-900/CeGdLaPrSmO-CP and 15%Ni-500/CeGdLaPrSmO-CP and shades the light on investigating their catalytic activity for CO2 hydrogenation to methane reaction and explains their performance based on their morphological and textural properties. The high entropy oxide support CeGdLaPrSmO that crystalized into fluorite structure was synthesized by coprecipitation method and the nickel was added to it by the wet impregnation. The nickel loaded high entropy oxide based catalysts exhibited maximum activity that reached up to 51.2 % of converting CO2 at 500 °C.
This study presents a one-dimensional model for nanofluid flow and heat transfer with nanoparticle aggregation. The model is governed by mass, momentum, energy and nanoparticle species conservation. The model is applied to investigate (1) nanoparticle aggregation under a quiescent condition and (2) heat transfer performance of nanofluid flow in pipes.
This paper presents an acoustic-based microfluidic platform for active manipulation and separation of micro-particles. An acoustic radiation force (ARF) is generated as a driving force on a piezoelectric Lithium Niobate (LiNbO3) wafer using patterned interdigitated transducer (IDT) electrodes on its surface to manipulate micro-particles precisely. On top of the wafer, a polydimethylsiloxane (PDMS) channel is bonded to allow the flow of the micro-particles. The supplied electric current to IDTs produces a vibration motion on the surface of the wafer. This vibratory motion has a distinct effect on different micro-particles depending on their size, density, and compressibility. In this paper, a separation of 6 μm from 14 μm diameter Polystyrene (PS) particles suspended in deionized water at a high flow rate of 200 μl/hr is demonstrated.
Liposomes are bilayer lipid membranes that can encapsulate drugs in the internal hydrophobic part of the hydrophilic bilayer. In targeted drug delivery, liposomes are used to deliver and target certain diseases to avoid any drug side effects. Instead of chemotherapy, treating breast cancer can be done using targeted drug delivery by Estrone conjugated liposomes that will reach the tumor site due to the receptors found on the membrane and nucleus of the cancer cells. Estrone liposomes can be synthesized using conventional techniques but have limitations. Microfluidics offers advantages over conventional techniques such as lower liposome size, better uniformity and reproducibility. Microfluidic hydrodynamic focusing (MHF) will be investigated for synthesis of estrone liposomes. In MHF, a stream of solvents containing the lipids is sandwiched between two buffer streams inside a microchannel. The small size scale involved enables rapid solvent exchange and initiates self-assembly of the lipids to form the required liposomes.
This work investigates the ability to sense glucose concentration in a water solution using a Reduced Graphene Oxide (rGO) based memristor. Planar memristors were fabricated using standard photolithography microfabrication techniques with different electrodes. The memristor sensor demonstrated the ability to detect different levels of D-glucose concentration represented as different Off/On resistance ratios of the device. This work is the first to establish a response of rGO-based memristor to glucose concentration, it opens the way to low-cost non-enzymatic screening for glucose level.
This paper discusses a possible design of a microfluidic contact lens that is highly sensitive to intraocular pressure (IOP). Normal eye pressure ranges between 10-21 mmHg, and eye pressure of greater than 21 mm Hg is directly related to glaucoma. The contact lens includes twelve capillary burst valves (CBV) designed with different widths, each corresponds to a specific IOP. The increase of IOP is represented by a noticeable fluid movement in the designed CBV's. The first designed CBV will burst when the IOP is larger than 10 mmHg, while the last one will burst when the IOP is larger than 37.5 mmHg. The uncertainty of the measured IOP is 2.5 mmHg, which is the difference between two adjacent burst pressures (BP).
