396 research outputs found
Arabic Cultural Program - Conversation with the author Hamdi Abu Golayyel
No full textThe Department of Arab & Islamic Civilization\u27s Arabic Cultural Program kicks off the year with an evening conversation with the author Hamdi Abu Golayyel on Saturday, November 12, 2016 at 6:00 pm in the Oriental Hall, Tahrir Campus. Abu Golayyel will discuss his collection Cairo\u27s Streets and Stories and will entertain questions from the audience
Embroidered rectangular split-ring resonators for material characterisation
No full textIn this paper, we report an embroidered rectangular split-ring resonator (SRR) operating at S band for sensing applications. We designed, fabricated and characterized the SRR sensor on a fabric that can conformally cover the surface of samples under investigation. The structure can be embroidered on any dielectric fabric at low cost using conventional embroidery methods. In addition, the method is suitable for the fabrication of large-scale arrays to cover large surfaces. We have demonstrated material characterization capability of the sensors using a specific design with a length of 60 mm and a width of 30 mm. We wrapped the sensors on low-density polyethylene (LDPE) bottles filled with deionized (DI) water and ethanol in our experiments and measured their resonant frequencies using a vector network analyzer (VNA). We measured the nominal resonant frequency of a specific sensor wrapped around an empty bottle as 2.06 GHz with a quality factor of 411. The shifts in resonant frequencies when the bottle was filled with ethanol and DI water are 42 MHz and 66 MHz, respectively
Microwave Sensing using Flexible Acoustofluidic Devices
No full textIn this work, a new concept for integrated biosensing technology is presented by combining the functionalities of metamaterial-based resonators and surface acoustofluidic devices on a single platform. The idea is to use a single structure in microwave frequencies for high-precision sensing and in radio frequencies for fluid manipulation. There is also a potential use of these structures in wearable biosensors by fabricating them on flexible substrates. The fabricated device operates in 5.5 GHz as a metamaterial-based resonator and in 40.3 MHz as a surface acoustic wave transducer for pumping application on a flexible substrate.</p
Streets and Stories: a conversation with Hamdi Abu Golayyel
No full textThe Department of Arab and Islamic Civilization\u27s Arabic Cultural Program kicked off the year with an evening conversation with the author Hamdi Abu Golayyel, on Saturday, November 12, 2016 at 6 pm in Oriental Hall at AUC Tahrir Square. Abu Golayyel discussed his collection, Cairo\u27s Streets and Stories, and entertained questions from the audience
An embroidered slot-loaded patch antenna for characterization of dielectric materials
No full textEmbroidery has been recently introduced as a new method to realize sensors especially for wearables. In this paper, we present a slot-loaded embroidered patch antenna to provide a simplified setup which allows the antenna to act as a stand-alone resonator. The design procedure, simulation and implementation of an embroidered sensor are presented and discussed. It is demonstrated that this structure can be used without any need for external antennas as a wireless sensor. To demonstrate the feasibility of this technique, the design process using a slot-loaded antenna to achieve a high Q antenna, fabricated on an FR4 substrate, is presented and discussed. This structure is then manufactured, with practical results shown to agree with simulated results. Using this as a basis for subsequent designs, an embroidered slot-loaded patch is presented and discussed. We demonstrate this capability in an experiment where a set of solvents inside plastic bottles were interrogated using the embroidered antennas
Embroidered Rectangular Split-Ring Resonators for the Characterization of Dielectric Materials
Get PDFIn this paper, we report an embroidered rectangular split-ring resonator (SRR) operating at S band for material characterization based on the differences in dielectric parameters. We designed, fabricated and characterized SRR sensors on a conventional fabric that can be conformally attached over the surface of samples under investigation. The structures are made of conductive threads and can be embroidered on any dielectric fabric at low cost using conventional embroidery methods. We have demonstrated material characterization capability of the sensors using a specific design with a length of 60 mm and a width of 30 mm. We wrapped the sensors on low-density polyethylene (LDPE) bottles filled with deionized (DI) water and common solvents (ethanol, methanol, isopropanol and acetone) in our experiments. We measured the nominal resonant frequency of a specific sensor wrapped around an empty bottle as 2.07 GHz. The shifts in resonant frequencies when the bottle was filled with the solvents follow the dielectric constants of the solvents
A MEMS-based terahertz detector with metamaterial-based absorber and optical interferometric readout
No full textA MEMS based novel THz detector structure is designed and realized by micro fabrication. The detector is then characterized to extract its mechanical performance. Operating in 0.5–2 THz band, the detector has a pixel size of 200 μm × 200 μm. Bimaterial suspension legs consist of Parylene-C and titanium, the pair of which provides a high mismatch in coefficients of thermal expansion. The pixel is a suspended Parylene-C structure having a 200 nm-thick titanium metallization. Operation principle relies on conversion of absorbed THz radiation into heat energy on the pixel. This increases the temperature of the free-standing microstructure that is thermally isolated from the substrate. The increase in temperature induces mechanical deflection due to bimaterial springs. The detector is designed to deliver a detectivity (D*) of 2 × 109 cm Hz−1/2/W and a refresh rate of 20 Hz
An integrated flexible platform of electromagnetic metamaterials and acoustofluidics on Kapton
No full textElectromagnetic metamaterial-based sensors are promising for wide-range of applications due to their high quality factors and their simple structure designs. On the other hand, surface acoustic wave (SAW)-based actuators have been studied for their capabilities in manipulating microfluids. In this paper, we propose a single flexible structure that can act as a metamaterial-based sensor in microwave frequencies, as well as a SAW actuator in radio frequencies. This feature makes our proposed design suitable for an integrated platform for both sensing and acoustofluidic manipulation purposes
Integrated sensing and actuation capabilities of flexible surface acoustic wave devices with metallic and polymer layers
No full textFlexible and bendable devices have become the key elements in the development of next-generation point-of-care systems and wearable technologies. In this paper, we report flexible surface acoustic wave (SAW) devices that are composed of a multilayer substrate; SAW devices are basically made of interdigital transducers (IDTs) that are patterned on a piezoelectric layer. In our fabricated devices, thin film of zinc oxide (ZnO), as the piezoelectric layer, is deposited on substrates made of trilayer of thin metal films (Nickel/Copper/Nickel) on top of a polyethylene terephthalate (PET) layer. We have characterized the devices in radio frequencies, and we have measured the response of the device to the temperature and the Ultraviolet (UV) light. Also, we have tested the actuation capability of our fabricated devices. We have successfully demonstrated that our fabricated devices can be employed as an integrated platform for sensing and actuation purposes using a single structure
Flexible platform of acoustofluidics and metamaterials with decoupled resonant frequencies
Get PDFThe key challenge for a lab-on-chip (LOC) device is the seamless integration of key elements of biosensing and actuation (e.g., biosampling or microfluidics), which are conventionally realised using different technologies. In this paper, we report a convenient and efficient LOC platform fabricated using an electrode patterned flexible printed circuit board (FPCB) pressed onto a piezoelectric film coated substrate, which can implement multiple functions of both acoustofluidics using surface acoustic waves (SAWs) and sensing functions using electromagnetic metamaterials, based on the same electrode on the FPCB. We explored the actuation capability of the integrated structure by pumping a sessile droplet using SAWs in the radio frequency range. We then investigated the hybrid sensing capability (including both physical and chemical ones) of the structure employing the concept of electromagnetic split-ring resonators (SRRs) in the microwave frequency range. The originality of this sensing work is based on the premise that the proposed structure contains three completely decoupled resonant frequencies for sensing applications and each resonance has been used as a separate physical or a chemical sensor. This feature compliments the acoustofluidic capability and is well-aligned with the goals set for a successful LOC device
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