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Hourieh Attarzadeh, Ye Xu, Trond Ytterdal
In this paper, a dual-mode low-power, high dynamic-range receiver circuit is designed for the interface with a capacitive micromachined ultrasonic transducer. The proposed ultrasound receiver chip enables the development of an in-probe digital beamforming imaging system. The flexibility of having two operation modes offers a high dynamic range with minimum power sacrifice. A prototype of the chip containing one receive channel, with one variable transimpedance amplifier (TIA) and one analog to digital converter (ADC) circuit is implemented...
July 18, 2017: IEEE Transactions on Biomedical Circuits and Systems
Venkatram Pepakayala, Scott R Green, Yogesh B Gianchandani
Resonant magnetoelastic devices are widely used as anti-theft tags and are also being investigated for a range of sensing applications. The vast majority of magnetoelastic devices are operated at resonance, and rely upon an external interface to wirelessly detect the resonant frequency, and other characteristics. For micromachined devices, this detection method must accommodate diminished signal strength and elevated resonant frequencies. Feedthrough of the interrogating stimulus to the detector also presents a significant challenge...
June 2017: ISSS J Micro Smart Syst
Ruxiu Liu, Waqas Waheed, Ningquan Wang, Ozgun Civelekoglu, Mert Boya, Chia-Heng Chu, A Fatih Sarioglu
A typical microfluidic device sorts, captures or fractionates sample constituents by exposing them to discriminating microenvironments. Direct electronic acquisition of such manipulation by a network of integrated sensors can provide a fast, integrated readout, replacing otherwise required microscopy. We have recently introduced a sensor technology, Microfluidic CODES, which allows us to multiplex resistive pulse sensors on a microfluidic device. Microfluidic CODES employs a network of micromachined coplanar electrodes such that particles passing over these electrodes produce distinguishable code sequences...
July 11, 2017: Lab on a Chip
Aleksander Sesek, Andrej Zemva, Janez Trontelj
BACKGROUND: The THz sensors using microbolometers as a sensing element are reported as one of the most sensitive room-temperature THz detectors suitable for THz imaging and spectroscopic applications. Microbolometer detectors are usually fabricated using different types of the MEMS technology. The patent for the detection system presented in this paper describes a method for microbolometer fabrication using a standard CMOS technology with advanced micromachining techniques. The measured sensitivity of the sensors fabricated by the patented method is 1000 V/W at an optimal frequency and is determined by the performance of a double-dipole antenna and quarter-wavelength resonant cavity...
July 4, 2017: Recent Patents on Nanotechnology
Milan Oeri, Wolfgang Bost, Nicolas Sénégond, Steffen Tretbar, Marc Fournelle
We report a target-enclosing, hybrid tomograph with a total of 768 elements based on capacitive micromachined ultrasound transducer technology and providing fast, high-resolution 2-D/3-D photoacoustic and ultrasound tomography tailored to finger imaging. A freely programmable ultrasound beamforming platform sampling data at 80 MHz was developed to realize plane wave transmission under multiple angles. A multiplexing unit enables the connection and control of a large number of elements. Fast image reconstruction is provided by GPU processing...
June 29, 2017: Ultrasound in Medicine & Biology
Huaduo Shi, Weiliang Shi, Ran Zhang, Junyi Zhai, Jinkui Chu, Shuxiang Dong
Micro/nanomaterials and devices have attracted great interest in recent years because of their extensive application prospects in almost all kinds of fields. However, the manipulations of the material at the micro/nanoscale, such as the separation or transfer of a micro/nano-object in the process of assembling micro/nanodevices, are quite difficult. In this paper, we present a micromachined micro-gripper made of photoresist material (SU-8) and driven by piezoelectric Pb(Mg,Nb)O3-PbTiO3 single crystal pieces...
June 2017: Review of Scientific Instruments
Gaszton Vizsnyiczai, Giacomo Frangipane, Claudio Maggi, Filippo Saglimbeni, Silvio Bianchi, Roberto Di Leonardo
Self-propelled bacteria can be integrated into synthetic micromachines and act as biological propellers. So far, proposed designs suffer from low reproducibility, large noise levels or lack of tunability. Here we demonstrate that fast, reliable and tunable bio-hybrid micromotors can be obtained by the self-assembly of synthetic structures with genetically engineered biological propellers. The synthetic components consist of 3D interconnected structures having a rotating unit that can capture individual bacteria into an array of microchambers so that cells contribute maximally to the applied torque...
June 28, 2017: Nature Communications
Hwall Min, Eugene Freeman, Weiwei Zhang, Chowdhury Ashraf, David L Allara, Adri C T van Duin, Srinivas Tadigadapa
In this paper we experimentally measure the adsorption kinetics of Human Serum Albumin (HSA) on a hydrophobic hexadecane thiolated gold surface. We use a micromachined quartz crystal resonators with a fundamental frequency of 70 MHz to accomplish these measurements in real time. In this work, we focus on two key results (i) asymptotic behavior of the sensor responses upon HSA adsorption and (ii) the jamming limit of adsorbed layer formed by both single-injection and multi-injection experiments with the same value of final concentration...
June 27, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Martin Pekař, Alexander F Kolen, Harm Belt, Frank van Heesch, Nenad Mihajlović, Imo E Hoefer, Tamas Szili-Török, Hendrik J Vos, Johan G Bosch, Gijs van Soest, Antonius F W van der Steen
In intracardiac echocardiography (ICE) it may be beneficial to generate ultrasound images acquired at multiple frequencies, having the possibility of high penetration or high-resolution imaging in a single device. The objective of the presented work is to test two frequency-tunable probe prototypes in a preclinical setting: a rigid probe having a diameter of 11 mm and a new flexible and steerable 12-Fr ICE catheter. Both probes feature a forward-looking 32-element capacitive micromachined ultrasonic transducer array (aperture of 2 × 2 mm(2)) operated in collapse mode, which allows for frequency tuning in the 6-MHz-18-MHz range...
June 20, 2017: Ultrasound in Medicine & Biology
Da-Chen Pang, Cheng-Min Chang
This paper presents the world's first transparent flexible capacitive micromachined ultrasonic transducer (CMUT) that was fabricated through a roll-lamination technique. This polymer-based CMUT has advantages of transparency, flexibility, and non-contacting detection which provide unique functions in display panel applications. Comprising an indium tin oxide-polyethylene terephthalate (ITO-PET) substrate, SU-8 sidewall and vibrating membranes, and silver nanowire transparent electrode, the transducer has visible-light transmittance exceeding 80% and can operate on curved surfaces with a 40 mm radius of curvature...
June 20, 2017: Sensors
Junhong Li, Wei Ren, Guoxiang Fan, Chenghao Wang
A square piezoelectric composite diaphragm was analyzed by the finite element method to enhance the sensitivity of a piezoelectric micromachined ultrasound transducer (pMUT). The structures of electrode and piezoelectric film were optimized and a centric electrode was designed to avoid the counteraction of stress in the centre and edges. In order to further improve the sensitivity; a pMUT with partially-etched piezoelectric film was adopted. The receive and transmit sensitivities of the pMUT were analyzed in details...
June 14, 2017: Sensors
Tong Lu, Eric J Markvicka, Yichu Jin, Carmel Majidi
When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM)...
June 23, 2017: ACS Applied Materials & Interfaces
Yoshitaka Yoshizumi, Hiroaki Suzuki
Two self-propelled micromachines were fabricated with gold/platinum micromotors that exhibit simple translational motion in a fuel solution. In each one, two micromotors were connected with a joint of polymer tube formed by stacking cationic poly(allylamine hydrochloride) (PAH) and anionic poly(acrylic acid) (PAA) using a layer-by-layer technique. A bent structure was created by making one longitudinal side of the joint more swellable with alkaline treatment. The joint containing fewer PAA/PAH bilayers was flexible and allowed a larger range of Brownian angular fluctuation...
June 16, 2017: ACS Applied Materials & Interfaces
Suleman Ayub, Luc J Gentet, Richárd Fiáth, Michael Schwaerzle, Mélodie Borel, François David, Péter Barthó, István Ulbert, Oliver Paul, Patrick Ruther
This article reports on the development, i.e., the design, fabrication, and validation of an implantable optical neural probes designed for in vivo experiments relying on optogenetics. The probes comprise an array of ten bare light-emitting diode (LED) chips emitting at a wavelength of 460 nm and integrated along a flexible polyimide-based substrate stiffened using a micromachined ladder-like silicon structure. The resulting mechanical stiffness of the slender, 250-μm-wide, 65-μm-thick, and 5- and 8-mm-long probe shank facilitates its implantation into neural tissue...
September 2017: Biomedical Microdevices
Stephen H Simpson, Pavel Zemánek, Onofrio M Maragò, Philip H Jones, Simon Hanna
Multiple scattering of light induces structured interactions, or optical binding forces, between collections of small particles. This has been extensively studied in the case of microspheres. However, binding forces are strongly shape dependent: here, we turn our attention to dielectric nanowires. Using a novel numerical model we uncover rich behavior. The extreme geometry of the nanowires produces a sequence of stationary and dynamic states. In linearly polarized light, thermally stable ladder-like structures emerge...
June 14, 2017: Nano Letters
Arvind Chandrasekaran, Nikita Kalashnikov, Roni Rayes, Claire Wang, Jonathan Spicer, Christopher Moraes
Innovation in microfluidics-based biological research has been aided by the growing accessibility of versatile microscale fabrication techniques, particularly in rapid prototyping of elastomeric polydimethylsiloxane (PDMS) based devices. However, the use of PDMS presents considerable and often unexpected limitations, particularly in interpreting and validating biological data. To rapidly prototype microfluidic culture systems in conventional plastics commonly used in cell culture, we developed 'thermal scribing', a one-step micromachining technique in which thermoplastics are locally patterned by a heated tip, moving in user-controlled patterns...
May 31, 2017: Lab on a Chip
Xiaoyue Jiang, Hao-Yen Tang, Yipeng Lu, Eldwin Ng, Julius Tsai, Bernhard Boser, David Horsley
In this paper, we present a single-chip 65x42 element ultrasonic pulse-echo fingerprint sensor with transmit beamforming based on piezoelectric micromachined ultrasonic transducers (PMUTs) directly bonded to a CMOS readout ASIC. The readout ASIC was realized in a standard 180 nm CMOS process with a 24V high voltage transistor option. Pulse-echo measurements are performed column-by-column in sequence using either one column or five columns to transmit the ultrasonic pulse at 20 MHz. Transmit beamforming is used to focus the ultrasonic beam at the imaging plane where the finger is located, increasing the ultrasonic pressure and narrowing the 3dB beam-width to 50 microns, a factor of 6...
May 11, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Chris Ceroici, Roger J Zemp
Capacitive micromachined ultrasonic transducers (CMUTs) promise many advantages over traditional piezoelectric transducers such as the potential to construct large, cost-effective 2-D arrays. To avoid wiring congestion issues associated with fully wired arrays, top-orthogonal-to-bottom electrode (TOBE) CMUT array architectures have proven to be a more practical alternative, using only 2N wires for an N ×N array. Optimally designing a TOBE CMUT array is a significant challenge due to the range of parameters from the device level up to the operating conditions of the entire array...
July 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Chupao Lin, Changrui Liao, Jia Wang, Jun He, Ying Wang, Zhengyong Li, Tianhang Yang, Feng Zhu, Kaiming Yang, Zhe Zhang, Yiping Wang
A fiber surface Bragg grating waveguide (BGW) fabricated in the surface of single-mode fiber by direct femtosecond laser inscription is demonstrated and successfully applied for refractive index (RI) measurements. Prior to laser inscription of the fiber surface BGW, an X-coupler is first inscribed across the fiber core to couple light from the core to the fiber surface. The light transmitted in the fiber surface BGW efficiently interacts with the surrounding medium due to a strong evanescent field, and obtains an acceptable RI sensitivity approaching ∼16  nm/RIU...
May 1, 2017: Optics Letters
Emil Karshalev, Chuanrui Chen, Gregor Marolt, Aída Martín, Isaac Campos, Roxanne Castillo, Tianlong Wu, Joseph Wang
All-in-one material for microrocket propulsion featuring acid-based bubble generation and magnetic guidance is presented. Electrochemically deposited iron serves as both a propellant, toward highly efficient self-propulsion in acidic environments, and as a magnetic component enabling complete motion control. The new microrockets display longer lifetime and higher propulsion efficiency compared to previously reported active metal zinc-based microrockets due to the chemical properties of iron and the unique structure of the microrockets...
June 2017: Small
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