Next Issue
Volume 7, September
Previous Issue
Volume 7, July
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.2
3.0
Journals
Micromachines
Volume 7
Issue 8
share announcement

Micromachines, Volume 7, Issue 8 (August 2016) – 18 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
5529 KiB  
Article
Microfluidic Neurons, a New Way in Neuromorphic Engineering?
by Timothée Levi and Teruo Fujii
Micromachines 2016, 7(8), 146; https://doi.org/10.3390/mi7080146 - 22 Aug 2016
Cited by 13 | Viewed by 7155
Abstract
This article describes a new way to explore neuromorphic engineering, the biomimetic artificial neuron using microfluidic techniques. This new device could replace silicon neurons and solve the issues of biocompatibility and power consumption. The biological neuron transmits electrical signals based on ion flow [...] Read more.
This article describes a new way to explore neuromorphic engineering, the biomimetic artificial neuron using microfluidic techniques. This new device could replace silicon neurons and solve the issues of biocompatibility and power consumption. The biological neuron transmits electrical signals based on ion flow through their plasma membrane. Action potentials are propagated along axons and represent the fundamental electrical signals by which information are transmitted from one place to another in the nervous system. Based on this physiological behavior, we propose a microfluidic structure composed of chambers representing the intra and extracellular environments, connected by channels actuated by Quake valves. These channels are equipped with selective ion permeable membranes to mimic the exchange of chemical species found in the biological neuron. A thick polydimethylsiloxane (PDMS) membrane is used to create the Quake valve membrane. Integrated electrodes are used to measure the potential difference between the intracellular and extracellular environments: the membrane potential. Full article
(This article belongs to the Special Issue MEMS/NEMS for Neuroscience)
►▼ Show Figures

Graphical abstract

2745 KiB  
Article
Thermoelectric Responsive Shape Memory Graphene/Hydro-Epoxy Composites for Actuators
by Yongkun Wang, Wenchao Tian, Jianqiang Xie and Yan Liu
Micromachines 2016, 7(8), 145; https://doi.org/10.3390/mi7080145 - 22 Aug 2016
Cited by 30 | Viewed by 5539
Abstract
A series of thermoelectric responsive shape memory hydro-epoxy (H-EP) composites filled with different contents of graphene were developed and characterized. Compared with traditional actuation materials, these novel shape memory composites exhibit attractive properties, such as light weight, large deformation, good processability and high [...] Read more.
A series of thermoelectric responsive shape memory hydro-epoxy (H-EP) composites filled with different contents of graphene were developed and characterized. Compared with traditional actuation materials, these novel shape memory composites exhibit attractive properties, such as light weight, large deformation, good processability and high response speed, making them good candidates for actuator materials. The effect of graphene content on the shape memory composites was studied in terms of mechanical, dynamic mechanical analysis (DMA), electrical properties, and thermoelectric responsive shape memory test. The results show that when graphene content was 2 wt %, the bend strength of the composite improved by about 47% with a storage modulus larger than other composites. The shape recovery ratio of the composites was about 100%, and the shape recovery speed increased with the increment of graphene content, applied voltage, and temperature. Due to the excellent actuation performance, the graphene/hydro-epoxy composite has potential applications in the actuator in the future. Full article
(This article belongs to the Special Issue Graphene Nano-Electro-Mechanical (NEM) Devices and Applications)
►▼ Show Figures

Graphical abstract

3856 KiB  
Article
Design, Analysis, and Verification of Ka-Band Pattern Reconfigurable Patch Antenna Using RF MEMS Switches
by Zhongliang Deng, Xubing Guo, Hao Wei, Jun Gan and Yucheng Wang
Micromachines 2016, 7(8), 144; https://doi.org/10.3390/mi7080144 - 17 Aug 2016
Cited by 16 | Viewed by 7298
Abstract
This paper proposes a radiating pattern reconfigurable antenna by employing RF Micro-electromechanical Systems (RF MEMS) switches. The antenna has a low profile and small size of 4 mm × 5 mm × 0.4 mm, and mainly consists of one main patch, two assistant [...] Read more.
This paper proposes a radiating pattern reconfigurable antenna by employing RF Micro-electromechanical Systems (RF MEMS) switches. The antenna has a low profile and small size of 4 mm × 5 mm × 0.4 mm, and mainly consists of one main patch, two assistant patches, and two RF MEMS switches. By changing the RF MEMS switches operating modes, the proposed antenna can switch among three radiating patterns (with main lobe directions of approximately −17.0°, 0° and +17.0°) at 35 GHz. The far-field vector addition model is applied to analyse the pattern. Comparing the measured results with analytical and simulated results, good agreements are obtained. Full article
►▼ Show Figures

Graphical abstract

3368 KiB  
Article
3D Finite Element Simulation of Graphene Nano-Electro-Mechanical Switches
by Jothiramalingam Kulothungan, Manoharan Muruganathan and Hiroshi Mizuta
Micromachines 2016, 7(8), 143; https://doi.org/10.3390/mi7080143 - 15 Aug 2016
Cited by 13 | Viewed by 6796
Abstract
In this paper, we report the finite element method (FEM) simulation of double-clamped graphene nanoelectromechanical (NEM) switches. Pull-in and pull-out characteristics are analyzed for graphene NEM switches with different dimensions and these are consistent with the experimental results. This numerical model is used [...] Read more.
In this paper, we report the finite element method (FEM) simulation of double-clamped graphene nanoelectromechanical (NEM) switches. Pull-in and pull-out characteristics are analyzed for graphene NEM switches with different dimensions and these are consistent with the experimental results. This numerical model is used to study the scaling nature of the graphene NEM switches. We show the possibility of achieving a pull-in voltage as low as 2 V for a 1.5-μm-long and 3-nm-thick nanocrystalline graphene beam NEM switch. In order to study the mechanical reliability of the graphene NEM switches, von Mises stress analysis is carried out. This analysis shows that a thinner graphene beam results in a lower von Mises stress. Moreover, a strong electrostatic force at the beam edges leads to a mechanical deflection at the edges larger than that around the center of the beam, which is consistent with the von Mises stress analysis. Full article
(This article belongs to the Special Issue Graphene Nano-Electro-Mechanical (NEM) Devices and Applications)
►▼ Show Figures

Graphical abstract

2609 KiB  
Article
High-Pressure Acceleration of Nanoliter Droplets in the Gas Phase in a Microchannel
by Yutaka Kazoe, Ippei Yamashiro, Kazuma Mawatari and Takehiko Kitamori
Micromachines 2016, 7(8), 142; https://doi.org/10.3390/mi7080142 - 15 Aug 2016
Cited by 4 | Viewed by 5036
Abstract
Microfluidics has been used to perform various chemical operations for pL–nL volumes of samples, such as mixing, reaction and separation, by exploiting diffusion, viscous forces, and surface tension, which are dominant in spaces with dimensions on the micrometer scale. To further develop this [...] Read more.
Microfluidics has been used to perform various chemical operations for pL–nL volumes of samples, such as mixing, reaction and separation, by exploiting diffusion, viscous forces, and surface tension, which are dominant in spaces with dimensions on the micrometer scale. To further develop this field, we previously developed a novel microfluidic device, termed a microdroplet collider, which exploits spatially and temporally localized kinetic energy. This device accelerates a microdroplet in the gas phase along a microchannel until it collides with a target. We demonstrated 6000-fold faster mixing compared to mixing by diffusion; however, the droplet acceleration was not optimized, because the experiments were conducted for only one droplet size and at pressures in the 10–100 kPa range. In this study, we investigated the acceleration of a microdroplet using a high-pressure (MPa) control system, in order to achieve higher acceleration and kinetic energy. The motion of the nL droplet was observed using a high-speed complementary metal oxide semiconductor (CMOS) camera. A maximum droplet velocity of ~5 m/s was achieved at a pressure of 1–2 MPa. Despite the higher fluid resistance, longer droplets yielded higher acceleration and kinetic energy, because droplet splitting was a determining factor in the acceleration and using a longer droplet helped prevent it. The results provide design guidelines for achieving higher kinetic energies in the microdroplet collider for various microfluidic applications. Full article
(This article belongs to the Special Issue Micro/Nano Devices for Chemical Analysis)
►▼ Show Figures

Graphical abstract

5507 KiB  
Article
Study of a Microfluidic Chip Integrating Single Cell Trap and 3D Stable Rotation Manipulation
by Liang Huang, Long Tu, Xueyong Zeng, Lu Mi, Xuzhou Li and Wenhui Wang
Micromachines 2016, 7(8), 141; https://doi.org/10.3390/mi7080141 - 12 Aug 2016
Cited by 22 | Viewed by 7696
Abstract
Single cell manipulation technology has been widely applied in biological fields, such as cell injection/enucleation, cell physiological measurement, and cell imaging. Recently, a biochip platform with a novel configuration of electrodes for cell 3D rotation has been successfully developed by generating rotating electric [...] Read more.
Single cell manipulation technology has been widely applied in biological fields, such as cell injection/enucleation, cell physiological measurement, and cell imaging. Recently, a biochip platform with a novel configuration of electrodes for cell 3D rotation has been successfully developed by generating rotating electric fields. However, the rotation platform still has two major shortcomings that need to be improved. The primary problem is that there is no on-chip module to facilitate the placement of a single cell into the rotation chamber, which causes very low efficiency in experiment to manually pipette single 10-micron-scale cells into rotation position. Secondly, the cell in the chamber may suffer from unstable rotation, which includes gravity-induced sinking down to the chamber bottom or electric-force-induced on-plane movement. To solve the two problems, in this paper we propose a new microfluidic chip with manipulation capabilities of single cell trap and single cell 3D stable rotation, both on one chip. The new microfluidic chip consists of two parts. The top capture part is based on the least flow resistance principle and is used to capture a single cell and to transport it to the rotation chamber. The bottom rotation part is based on dielectrophoresis (DEP) and is used to 3D rotate the single cell in the rotation chamber with enhanced stability. The two parts are aligned and bonded together to form closed channels for microfluidic handling. Using COMSOL simulation and preliminary experiments, we have verified, in principle, the concept of on-chip single cell traps and 3D stable rotation, and identified key parameters for chip structures, microfluidic handling, and electrode configurations. The work has laid a solid foundation for on-going chip fabrication and experiment validation. Full article
(This article belongs to the Special Issue Advances in Microfluidic Devices for Cell Handling and Analysis)
►▼ Show Figures

Graphical abstract

5891 KiB  
Article
A Method of Three-Dimensional Micro-Rotational Flow Generation for Biological Applications
by Yaxiaer Yalikun, Yasunari Kanda and Keisuke Morishima
Micromachines 2016, 7(8), 140; https://doi.org/10.3390/mi7080140 - 10 Aug 2016
Cited by 15 | Viewed by 6592
Abstract
We report a convenient method to create a three-dimensional micro-rotational fluidic platform for biological applications in the direction of a vertical plane (out-of-plane) without contact in an open space. Unlike our previous complex fluidic manipulation system, this method uses a micro-rotational flow generated [...] Read more.
We report a convenient method to create a three-dimensional micro-rotational fluidic platform for biological applications in the direction of a vertical plane (out-of-plane) without contact in an open space. Unlike our previous complex fluidic manipulation system, this method uses a micro-rotational flow generated near a single orifice when the solution is pushed from the orifice by using a single pump. The three-dimensional fluidic platform shows good potential for fluidic biological applications such as culturing, stimulating, sorting, and manipulating cells. The pattern and velocity of the micro-rotational flow can be controlled by tuning the parameters such as the flow rate and the liquid-air interface height. We found that bio-objects captured by the micro-rotational flow showed self-rotational motion and orbital motion. Furthermore, the path length and position, velocity, and pattern of the orbital motion of the bio-object could be controlled. To demonstrate our method, we used embryoid body cells. As a result, the orbital motion had a maximum length of 2.4 mm, a maximum acceleration of 0.63 m/s2, a frequency of approximately 0.45 Hz, a maximum velocity of 15.4 mm/s, and a maximum rotation speed of 600 rpm. The capability to have bio-objects rotate or move orbitally in three dimensions without contact opens up new research opportunities in three-dimensional microfluidic technology. Full article
(This article belongs to the Special Issue Micro/Nano Devices for Chemical Analysis)
►▼ Show Figures

Graphical abstract

4412 KiB  
Article
A Reconfigurable Microfluidics Platform for Microparticle Separation and Fluid Mixing
by Young Ki Hahn, Daehyup Hong, Joo H. Kang and Sungyoung Choi
Micromachines 2016, 7(8), 139; https://doi.org/10.3390/mi7080139 - 8 Aug 2016
Cited by 13 | Viewed by 7137
Abstract
Microfluidics is an engineering tool used to control and manipulate fluid flows, with practical applications for lab-on-a-chip, point-of-care testing, and biological/medical research. However, microfluidic platforms typically lack the ability to create a fluidic duct, having an arbitrary flow path, and to change the [...] Read more.
Microfluidics is an engineering tool used to control and manipulate fluid flows, with practical applications for lab-on-a-chip, point-of-care testing, and biological/medical research. However, microfluidic platforms typically lack the ability to create a fluidic duct, having an arbitrary flow path, and to change the path as needed without additional design and fabrication processes. To address this challenge, we present a simple yet effective approach for facile, on-demand reconfiguration of microfluidic channels using flexible polymer tubing. The tubing provides both a well-defined, cross-sectional geometry to allow reliable fluidic operation and excellent flexibility to achieve a high degree of freedom for reconfiguration of flow pathways. We demonstrate that microparticle separation and fluid mixing can be successfully implemented by reconfiguring the shape of the tubing. The tubing is coiled around a 3D-printed barrel to make a spiral microchannel with a constant curvature for inertial separation of microparticles. Multiple knots are also made in the tubing to create a highly tortuous flow path, which induces transverse secondary flows, Dean flows, and, thus, enhances the mixing of fluids. The reconfigurable microfluidics approach, with advantages including low-cost, simplicity, and ease of use, can serve as a promising complement to conventional microfabrication methods, which require complex fabrication processes with expensive equipment and lack a degree of freedom for reconfiguration. Full article
(This article belongs to the Special Issue Insights and Advancements in Microfluidics)
►▼ Show Figures

Graphical abstract

7744 KiB  
Article
An Implantable Intravascular Pressure Sensor for a Ventricular Assist Device
by Luigi Brancato, Grim Keulemans, Tom Verbelen, Bart Meyns and Robert Puers
Micromachines 2016, 7(8), 135; https://doi.org/10.3390/mi7080135 - 8 Aug 2016
Cited by 32 | Viewed by 8971
Abstract
The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS) pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD). A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick [...] Read more.
The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS) pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD). A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick film process. A commercial sub-millimeter piezoresistive sensor is attached to an alumina substrate, and a double coating of polydimethylsiloxane (PDMS) and parylene-C is applied. The final size of the packaged device is 2.6 mm by 3.6 mm by 1.8 mm. A prototype electronic circuit for conditioning and read-out of the pressure signal is developed, satisfying the VAD-specific requirements of low power consumption (less than 14.5 mW in continuous mode) and small form factor. The packaged sensor has been submitted to extensive in vitro tests. The device displayed a temperature-independent sensitivity (12 μ V/V/mmHg) and good in vitro stability when exposed to the continuous flow of saline solution (less than 0.05 mmHg/day drift after 50 h). During in vivo validation, the transducer has been successfully used to record the arterial pressure waveform of a female sheep. A small, intravascular sensor to continuously register the blood pressure at the inflow and the outflow of a VAD is developed and successfully validated in vivo. Full article
(This article belongs to the Special Issue Implantable Microsystems)
►▼ Show Figures

Graphical abstract

10402 KiB  
Article
Fluid-Mediated Stochastic Self-Assembly at Centimetric and Sub-Millimetric Scales: Design, Modeling, and Control
by Bahar Haghighat, Massimo Mastrangeli, Grégory Mermoud, Felix Schill and Alcherio Martinoli
Micromachines 2016, 7(8), 138; https://doi.org/10.3390/mi7080138 - 6 Aug 2016
Cited by 13 | Viewed by 6334
Abstract
Stochastic self-assembly provides promising means for building micro-/nano-structures with a variety of properties and functionalities. Numerous studies have been conducted on the control and modeling of the process in engineered self-assembling systems constituted of modules with varied capabilities ranging from completely reactive nano-/micro-particles [...] Read more.
Stochastic self-assembly provides promising means for building micro-/nano-structures with a variety of properties and functionalities. Numerous studies have been conducted on the control and modeling of the process in engineered self-assembling systems constituted of modules with varied capabilities ranging from completely reactive nano-/micro-particles to intelligent miniaturized robots. Depending on the capabilities of the constituting modules, different approaches have been utilized for controlling and modeling these systems. In the quest of a unifying control and modeling framework and within the broader perspective of investigating how stochastic control strategies can be adapted from the centimeter-scale down to the (sub-)millimeter-scale, as well as from mechatronic to MEMS-based technology, this work presents the outcomes of our research on self-assembly during the past few years. As the first step, we leverage an experimental platform to study self-assembly of water-floating passive modules at the centimeter scale. A dedicated computational framework is developed for real-time tracking, modeling and control of the formation of specific structures. Using a similar approach, we then demonstrate controlled self-assembly of microparticles into clusters of a preset dimension in a microfluidic chamber, where the control loop is closed again through real-time tracking customized for a much faster system dynamics. Finally, with the aim of distributing the intelligence and realizing programmable self-assembly, we present a novel experimental system for fluid-mediated programmable stochastic self-assembly of active modules at the centimeter scale. The system is built around the water-floating 3-cm-sized Lily robots specifically designed to be operative in large swarms and allows for exploring the whole range of fully-centralized to fully-distributed control strategies. The outcomes of our research efforts extend the state-of-the-art methodologies for designing, modeling and controlling massively-distributed, stochastic self-assembling systems at different length scales, constituted of modules from centimetric down to sub-millimetric size. As a result, our work provides a solid milestone in structure formation through controlled self-assembly. Full article
(This article belongs to the Special Issue Building by Self-Assembly)
►▼ Show Figures

Graphical abstract

15633 KiB  
Article
Stacked Integration of MEMS on LSI
by Masayoshi Esashi and Shuji Tanaka
Micromachines 2016, 7(8), 137; https://doi.org/10.3390/mi7080137 - 5 Aug 2016
Cited by 19 | Viewed by 8722
Abstract
Two stacked integration methods have been developed to enable advanced microsystems of microelectromechanical systems (MEMS) on large scale integration (LSI). One is a wafer level transfer of MEMS fabricated on a carrier wafer to a LSI wafer. The other is the use of [...] Read more.
Two stacked integration methods have been developed to enable advanced microsystems of microelectromechanical systems (MEMS) on large scale integration (LSI). One is a wafer level transfer of MEMS fabricated on a carrier wafer to a LSI wafer. The other is the use of electrical interconnections using through-Si vias from the structure of a MEMS wafer on a LSI wafer. The wafer level transfer methods are categorized to film transfer, device transfer connectivity last, and immediate connectivity at device transfer. Applications of these transfer methods are film bulk acoustic resonator (FBAR) on LSI, lead zirconate titanate (Pb(Zr,Ti)O3) (PZT) MEMS switch on LSI, and surface acoustic wave (SAW) resonators on LSI using respective methods. A selective transfer process was developed for multiple SAW filters on LSI. Tactile sensors and active matrix electron emitters for massive parallel electron beam lithography were developed using the through-Si vias. Full article
(This article belongs to the Special Issue 3D Integration Technologies for MEMS)
►▼ Show Figures

Graphical abstract

2272 KiB  
Article
A Reduced Graphene Oxide Based Radio Frequency Glucose Sensing Device Using Multi-Dimensional Parameters
by Byeongho Park, Hyung Goo Park, Jae-hoon Ji, Jinsoo Cho and Seong Chan Jun
Micromachines 2016, 7(8), 136; https://doi.org/10.3390/mi7080136 - 5 Aug 2016
Cited by 15 | Viewed by 6792
Abstract
A reduced graphene oxide (RGO) based glucose sensor using a radio frequency (RF) signal is demonstrated. An RGO with outstanding electrical property was employed as the interconnector material between signal electrodes in an RF electric circuit, and it was functionalized with phenylbutyric acid [...] Read more.
A reduced graphene oxide (RGO) based glucose sensor using a radio frequency (RF) signal is demonstrated. An RGO with outstanding electrical property was employed as the interconnector material between signal electrodes in an RF electric circuit, and it was functionalized with phenylbutyric acid (PBA) as a linker molecule to bind glucoses. By adding glucose solution, the fabricated sensor with RGO and PBA showed detecting characteristics in RF signal transmission and reflection. Frequency dependent electrical parameters such as resistance, inductance, shunt conductance and shunt capacitance were extracted from the RF results under the equivalent circuit model. These parameters also provided sensing characteristics of glucose with different concentrations. Using these multi-dimensional parameters, the RF sensor device detected glucose levels in the range of 1–4 mM, which ordinarily covers the testing range for diabetes or medical examination. The RGO based RF sensor, which fits well to a linear curve with fine stability, holds considerable promise for biomaterials detection, including glucose. Full article
(This article belongs to the Special Issue Graphene Nano-Electro-Mechanical (NEM) Devices and Applications)
►▼ Show Figures

Graphical abstract

4918 KiB  
Article
Integration of a Droplet-Based Microfluidic System and Silicon Nanoribbon FET Sensor
by Roodabeh Afrasiabi, Lovisa M. Soderberg, Haakan N. Joensson, Per Björk, Helene Andersson Svahn and Jan Linnros
Micromachines 2016, 7(8), 134; https://doi.org/10.3390/mi7080134 - 5 Aug 2016
Cited by 7 | Viewed by 7247
Abstract
We present a novel microfluidic system that integrates droplet microfluidics with a silicon nanoribbon field-effect transistor (SiNR FET), and utilize this integrated system to sense differences in pH. The device allows for selective droplet transfer to a continuous water phase, actuated by dielectrophoresis, [...] Read more.
We present a novel microfluidic system that integrates droplet microfluidics with a silicon nanoribbon field-effect transistor (SiNR FET), and utilize this integrated system to sense differences in pH. The device allows for selective droplet transfer to a continuous water phase, actuated by dielectrophoresis, and subsequent detection of the pH level in the retrieved droplets by SiNR FETs on an electrical sensor chip. The integrated microfluidic system demonstrates a label-free detection method for droplet microfluidics, presenting an alternative to optical fluorescence detection. In this work, we were able to differentiate between droplet trains of one pH-unit difference. The pH-based detection method in our integrated system has the potential to be utilized in the detection of biochemical reactions that induce a pH-shift in the droplets. Full article
(This article belongs to the Special Issue Droplet Microfluidics: Techniques and Technologies, Volume II)
►▼ Show Figures

Graphical abstract

4724 KiB  
Article
A Modified Lattice Configuration Design for Compact Wideband Bulk Acoustic Wave Filter Applications
by Qingrui Yang, Wei Pang, Daihua Zhang and Hao Zhang
Micromachines 2016, 7(8), 133; https://doi.org/10.3390/mi7080133 - 5 Aug 2016
Cited by 17 | Viewed by 8320
Abstract
High-performance bulk acoustic wave (BAW) filters have been widely applied in the advanced radio frequency (RF) wireless communication systems in the past decade. However, the demand for filters with large bandwidth, up to 10%, still puts a significant stress on the typical aluminum [...] Read more.
High-performance bulk acoustic wave (BAW) filters have been widely applied in the advanced radio frequency (RF) wireless communication systems in the past decade. However, the demand for filters with large bandwidth, up to 10%, still puts a significant stress on the typical aluminum nitride (AlN)-based BAW filters. In this work, a modified lattice configuration is proposed to achieve a wideband filter response using AlN-based BAW resonators. The single stage of this novel topology comprises two auxiliary inductors paralleled in the balanced input and output of the conventional lattice topology. In multi-stage configuration, adjacent two auxiliary inductors can be combined into one; thus, the number of auxiliary inductors decreases exponentially, enabling the compact integration of filter chips. The circuit analysis is performed to reveal the working principle of this configuration. The systematic design methodology is developed ranging from the schematic design to the electromagnetic (EM) simulation. For proof-of-concept validation purposes, a prototype film bulk acoustic wave filter in this configuration is designed and fabricated. The measured 3-dB bandwidth is 400 MHz at the central frequency of 3.25 GHz (12.3% relative bandwidth), which demonstrates a huge superiority in contrast with the conventional ladder and lattice topologies. Full article
(This article belongs to the Special Issue Applications of Advanced Nanomaterials on Microelectronic Devices and MEMS)
►▼ Show Figures

Graphical abstract

4605 KiB  
Letter
Fabrication of a Cell Fixation Device for Robotic Cell Microinjection
by Yu Xie, Yunlei Zhou, Wenming Xi, Feng Zeng and Songyue Chen
Micromachines 2016, 7(8), 131; https://doi.org/10.3390/mi7080131 - 4 Aug 2016
Cited by 2 | Viewed by 4902
Abstract
Automation of cell microinjection greatly reduces operational difficulty, but cell fixation remains a challenge. Here, we describe an innovative device that solves the fixation problem without single-cell operation. The microarray cylinder is designed with a polydimethylsiloxane (PDMS) material surface to control the contact [...] Read more.
Automation of cell microinjection greatly reduces operational difficulty, but cell fixation remains a challenge. Here, we describe an innovative device that solves the fixation problem without single-cell operation. The microarray cylinder is designed with a polydimethylsiloxane (PDMS) material surface to control the contact force between cells and the material. Data show that when the injection velocity exceeds 1.5 mm/s, microinjection success rate is over 80%. The maximum value of the adhesion force between the PDMS plate and the cell is 0.0138 N, and the need can be met in practical use of the robotic microinjection. Full article
(This article belongs to the Special Issue Microdevices and Microsystems for Cell Manipulation)
►▼ Show Figures

Graphical abstract

5515 KiB  
Article
Characterization of a Laterally Oscillating Microresonator Operating in the Nonlinear Region
by Aditya Ramanan, Yu Xuan Teoh, Wei Ma and Wenjing Ye
Micromachines 2016, 7(8), 132; https://doi.org/10.3390/mi7080132 - 2 Aug 2016
Cited by 9 | Viewed by 4689
Abstract
Microresonators are popular structures used in a variety of applications. They generally operate in the linear region where the vibration amplitude is limited, thereby limiting the signal-to-noise ratio. The nonlinear vibration region, where amplitudes and, consequently, the signal-to-noise ratio are relatively large, is [...] Read more.
Microresonators are popular structures used in a variety of applications. They generally operate in the linear region where the vibration amplitude is limited, thereby limiting the signal-to-noise ratio. The nonlinear vibration region, where amplitudes and, consequently, the signal-to-noise ratio are relatively large, is generally avoided owing to instabilities and complexities in analysing the vibrations. In this work, a nonlinear dynamic model with a damping constant obtained from Monte Carlo simulation was derived to describe the vibration responses of microresonators operating in the nonlinear region. A laterally oscillating comb-drive driven resonator was designed, fabricated and characterized at various pressures and driving signals to validate the model. A simple method to extract the quality factor of the resonator in the nonlinear region was also proposed. The measured quality factors were compared with those obtained from the nonlinear model and a good agreement was obtained. Full article
(This article belongs to the Special Issue Microresonators)
►▼ Show Figures

Graphical abstract

4096 KiB  
Review
Organ-Tumor-on-a-Chip for Chemosensitivity Assay: A Critical Review
by Navid Kashaninejad, Mohammad Reza Nikmaneshi, Hajar Moghadas, Amir Kiyoumarsi Oskouei, Milad Rismanian, Maryam Barisam, Mohammad Said Saidi and Bahar Firoozabadi
Micromachines 2016, 7(8), 130; https://doi.org/10.3390/mi7080130 - 28 Jul 2016
Cited by 70 | Viewed by 13739
Abstract
With a mortality rate over 580,000 per year, cancer is still one of the leading causes of death worldwide. However, the emerging field of microfluidics can potentially shed light on this puzzling disease. Unique characteristics of microfluidic chips (also known as micro-total analysis [...] Read more.
With a mortality rate over 580,000 per year, cancer is still one of the leading causes of death worldwide. However, the emerging field of microfluidics can potentially shed light on this puzzling disease. Unique characteristics of microfluidic chips (also known as micro-total analysis system) make them excellent candidates for biological applications. The ex vivo approach of tumor-on-a-chip is becoming an indispensable part of personalized medicine and can replace in vivo animal testing as well as conventional in vitro methods. In tumor-on-a-chip, the complex three-dimensional (3D) nature of malignant tumor is co-cultured on a microfluidic chip and high throughput screening tools to evaluate the efficacy of anticancer drugs are integrated on the same chip. In this article, we critically review the cutting edge advances in this field and mainly categorize each tumor-on-a-chip work based on its primary organ. Specifically, design, fabrication and characterization of tumor microenvironment; cell culture technique; transferring mechanism of cultured cells into the microchip; concentration gradient generators for drug delivery; in vitro screening assays of drug efficacy; and pros and cons of each microfluidic platform used in the recent literature will be discussed separately for the tumor of following organs: (1) Lung; (2) Bone marrow; (3) Brain; (4) Breast; (5) Urinary system (kidney, bladder and prostate); (6) Intestine; and (7) Liver. By comparing these microchips, we intend to demonstrate the unique design considerations of each tumor-on-a-chip based on primary organ, e.g., how microfluidic platform of lung-tumor-on-a-chip may differ from liver-tumor-on-a-chip. In addition, the importance of heart–liver–intestine co-culture with microvasculature in tumor-on-a-chip devices for in vitro chemosensitivity assay will be discussed. Such system would be able to completely evaluate the absorption, distribution, metabolism, excretion and toxicity (ADMET) of anticancer drugs and more realistically recapitulate tumor in vivo-like microenvironment. Full article
(This article belongs to the Special Issue Microfluidic Bioreactors and Organ-on-Chip Devices for Drug Screening and Disease Modeling)
►▼ Show Figures

Graphical abstract

5963 KiB  
Article
Application of Robust, Packaged Long-Period Fiber Grating for Strain Measurement
by Ke-Ping Ma, Chao-Wei Wu, Tso-Sheng Hsieh, Min-Yuan Hsieh and Chia-Chin Chiang
Micromachines 2016, 7(8), 129; https://doi.org/10.3390/mi7080129 - 26 Jul 2016
Cited by 12 | Viewed by 5252
Abstract
This paper proposes an optical fiber strain sensor based on packaged long-period fiber gratings (PLPFG) which is fabricated by the micro-electromechanical systems (MEMS) process and packaged with poly-dimethylsiloxane (PDMS) polymer materials. The optical fiber sensor packaged with PDMS improves robustness effectively. The proposed [...] Read more.
This paper proposes an optical fiber strain sensor based on packaged long-period fiber gratings (PLPFG) which is fabricated by the micro-electromechanical systems (MEMS) process and packaged with poly-dimethylsiloxane (PDMS) polymer materials. The optical fiber sensor packaged with PDMS improves robustness effectively. The proposed PLPFG sensors have periods of 610, 650, 660 μm and fiber diameter of 48, 60, 72 μm, respectively. The resonance dip of the PLPFG grows when a strain loaded onto the sensor. The results show that the largest strain sensitivity of the PLPFG strain sensor was −0.0652 dB/με from 0–1200 με and the linearity (R2) was 0.9812. Accordingly, the proposed PLPFG sensor has good potential for high-sensitivity strain sensing applications. Full article
(This article belongs to the Special Issue Applications of Advanced Nanomaterials on Microelectronic Devices and MEMS)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-18
Previous Issue
Next Issue
Back to TopTop