2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013
This paper presents a state-of-the-art intelligent acoustic emission (AE) and mechanical impedanc... more This paper presents a state-of-the-art intelligent acoustic emission (AE) and mechanical impedance hybrid sensor (Fig. 1). The sensor can be operated in two modes: 1) sensing acoustic waves emitted from an external source with the function of being able to detect the static force at installation; 2) measuring the mechanical impedance of the interested object/material by exerting a dynamic force on the object and sensing its feedback velocity. This unique sensor is composed of three major core elements: a micromachined wavy-shaped sensing element made with multi-layer piezoelectric polymer (PVDF) films; a micromachined strain gage made on a patterned SU-8 flexible substrate for force/velocity detection; a diced PZT plate for AE sensing and AE coupling to PVDF element. The device working principle, fabrication and testing are described in the text. Experimental results of pencil lead fracture and material characterization demonstrate the functionality of the developed sensor.
This paper presents a stretchable and flexible acoustic emission (AE) sensor composed of patterne... more This paper presents a stretchable and flexible acoustic emission (AE) sensor composed of patterned upper, lower piezoelectric film foils, magnets and stereolithographic structures. The proposed device possesses the following novelties. The piezoelectric sensing structures with magnetic repulsion is effective for AE signal coupling. The lower piezoelectric serpentine-shaped AE detection structure with stretchable and flexible characteristics allows sensing various curved surfaces. Additionally, the contact force between the sensing target and AE sensor can be evaluated by monitoring the structural characteristic change of the upper piezoelectric structure of the AE sensor. The magnetic-repulsion-enhanced AE sensor exhibits a better bandwidth compared to that with only a lower AE sensing structure. Also, the fabricated sensor subjected to a sensing target force ranging from 4.98 to 14.85 mN resulting in a frequency change of the piezoelectric sensing beam of the upper foil from 20.073...
TRANSDUCERS 2009 - 2009 International Solid-State Sensors, Actuators and Microsystems Conference, 2009
This paper presents a novel three-dimensional (3D) four-electrode ion polymer metal composite (IP... more This paper presents a novel three-dimensional (3D) four-electrode ion polymer metal composite (IPMC) actuator with accurate omnidirectional control capability. The developed 3D IPMC transducer is used to enclose a section of optical fiber, thereby allowing electronic directional control of conducted laser light. This could be useful in applications such as microendoscopic ocular surgery. The fabricated device with the IPMC actuator
Abstract This paper presents an embedded sensing system for precisely measuring acceleration and ... more Abstract This paper presents an embedded sensing system for precisely measuring acceleration and temperature of interest points on a ball screw structure and diagnosis of different ball-screw preloads based on processing acquired signals with further classification using the support vector machine (SVM) method. The sensing system consists of a sensing unit and a hardware signal-processing unit. The core sensors utilize a MEMS-type accelerometer and glass-type SMD PT-100, integrated into a 1 cm×1 cm circuit board and packaged with a metal housing sensing unit with a dimension less than 1.5 cm 3 . The sensing unit is embedded into the screw nut of a designed preload-adjustable ball screw, installed on a computer-controlled single-axis stage for testing. Acquired signals with good noise immunity in an industrial environment are achieved through the developed hardware signal-processing unit. Measured acceleration and temperature data for different ball-screw preload levels based on time and frequency domain analysis are performed. The results demonstrate achieving diagnosis of a ball-screw preload within 20 s, with a preload level classification reaching nearly 100%. The developed sensing system and analysis method can apply to monitor ball-screw health and would be very useful in industrial applications.
... pared with solar or electromagnetic generators, design of piezoelectric microgenerators requi... more ... pared with solar or electromagnetic generators, design of piezoelectric microgenerators requires relatively ... SP, White NM (2001) Towards a piezoelectric vibration-powered microgenerator. ... NM, Glynne-Jones P, Beeby SP (2001) A novel thick-film piezoelectric micro-generator. ...
This paper proposes a tunable-focus liquid lens implemented with a simple cylindrical container s... more This paper proposes a tunable-focus liquid lens implemented with a simple cylindrical container structure and liquid as the lens material. The cylindrical container was constructed using a Pb [Zr(0.52)Ti(0.48)]O(3) (PZT) ring transducer and a polydimethylsiloxane membrane that was attached to a flat side of the transducer. The free surface of the liquid in the cylindrical container can be driven as a static-like convex lens with different curvatures because the higher-order harmonic resonance of the PZT transducer was electrically controlled. Based on a capillary-force-dominant design, the activated liquid lens maintained surface curvature in an arbitrary orientation without a gravitational effect. Profiles of the liquid lenses were characterized with the driving voltages of the transducer ranging from 12 to 60 V peak-to-peak (Vpp) at a resonant frequency of 460 kHz. The temperature effects on the lenses caused by the continuous operation of the transducer were measured. Images showed the various curvatures of the lenses with a range of actuation voltages. A change in focal length of eight times (5.72 to 46.03 cm) was demonstrated within the 10 Vpp variation of the driving voltage. For the characterized liquid lenses, the distortion was less than 2%, and the modulation transfer function reached 63 line pairs per mm (lp/mm) using ZEMAX analysis.
Page 1. Micropump based on PZT unimorph and one-way parylene valves This article has been downloa... more Page 1. Micropump based on PZT unimorph and one-way parylene valves This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2004 J. Micromech. Microeng. 14 429 (http://iopscience.iop.org/0960-1317/14/4/001) ...
The present paper examined a novel micromachined column structured Ion Polymer Metal Composite (I... more The present paper examined a novel micromachined column structured Ion Polymer Metal Composite (IPMC) actuator with multidirectional control capability. The developed 4-electrode transducer enclosed a section of optical fiber, thereby allowing electronic directional control of conducted laser light. The fabricated device with IPMC actuator dimensions of 5 mm x 2 mm x 1 mm reached a maximum displacement of 400 μm when a square wave of 9 V was applied to the top-bottom electrode pair. Displacements in different directions and moving angles were characterized with side-side and top-right electrode pairs connected to the actuating signals. Furthermore, the generating moment per volt per second by the transducer was analyzed. The maximum value of approximately 200 μN*m/V/s was displayed when the device actuated with the side-side electrode pair. Controlling the developed IPMC actuator moved the laser beam in multiple directions. This device could be promising for biomedical applications such as microendoscopic ocular surgery.
We fabricated three piezoelectric components (PZT) that can produce ultrasonic waves with various... more We fabricated three piezoelectric components (PZT) that can produce ultrasonic waves with various generated power in order to improve the delivery of DNA molecule and polymer/DNA complexes into cells. Two cationic polymers (PEI and PDMAEMA) were interacted with DNA to form nano-scaled DNA/polymer complexes with/without the help of PZT devices. The application of PZT devices under optimal conditions helped to avoid cytotoxicity and greatly increased the transfection (DNA delivery) efficiency of these complexes in mammalian cells. The cytotoxicity and transfection efficiency were found to be correlated with the PZT-generated power, waveforms and duration of ultrasonic treatment. There was no observable cytotoxicity in our experimental models and, a maximum transfection efficiency 700% greater than that of polymer/DNA complexes without applying ultrasound was achieved. The transfection efficiency of plain polymer/DNA complexes (without PZT treatment) corresponded to a 630-fold increase in comparison to the naked DNA. The waveforms of generated ultrasound greatly influenced the transfection efficiency, while cytotoxicity was not significantly affected. This means that, for optimal DNA delivery, duration of the peak voltage (Vmax/Div) also plays a role. In addition, the generated waves from PZT do not cause dissociation of polymer/DNA complexes or a change in the particle sizes of these complexes. In conclusion, these results suggest that the operation of PZT devices can be a tunable/safe way to greatly improve DNA delivery for gene therapy.
2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013
This paper presents a state-of-the-art intelligent acoustic emission (AE) and mechanical impedanc... more This paper presents a state-of-the-art intelligent acoustic emission (AE) and mechanical impedance hybrid sensor (Fig. 1). The sensor can be operated in two modes: 1) sensing acoustic waves emitted from an external source with the function of being able to detect the static force at installation; 2) measuring the mechanical impedance of the interested object/material by exerting a dynamic force on the object and sensing its feedback velocity. This unique sensor is composed of three major core elements: a micromachined wavy-shaped sensing element made with multi-layer piezoelectric polymer (PVDF) films; a micromachined strain gage made on a patterned SU-8 flexible substrate for force/velocity detection; a diced PZT plate for AE sensing and AE coupling to PVDF element. The device working principle, fabrication and testing are described in the text. Experimental results of pencil lead fracture and material characterization demonstrate the functionality of the developed sensor.
This paper presents a stretchable and flexible acoustic emission (AE) sensor composed of patterne... more This paper presents a stretchable and flexible acoustic emission (AE) sensor composed of patterned upper, lower piezoelectric film foils, magnets and stereolithographic structures. The proposed device possesses the following novelties. The piezoelectric sensing structures with magnetic repulsion is effective for AE signal coupling. The lower piezoelectric serpentine-shaped AE detection structure with stretchable and flexible characteristics allows sensing various curved surfaces. Additionally, the contact force between the sensing target and AE sensor can be evaluated by monitoring the structural characteristic change of the upper piezoelectric structure of the AE sensor. The magnetic-repulsion-enhanced AE sensor exhibits a better bandwidth compared to that with only a lower AE sensing structure. Also, the fabricated sensor subjected to a sensing target force ranging from 4.98 to 14.85 mN resulting in a frequency change of the piezoelectric sensing beam of the upper foil from 20.073...
TRANSDUCERS 2009 - 2009 International Solid-State Sensors, Actuators and Microsystems Conference, 2009
This paper presents a novel three-dimensional (3D) four-electrode ion polymer metal composite (IP... more This paper presents a novel three-dimensional (3D) four-electrode ion polymer metal composite (IPMC) actuator with accurate omnidirectional control capability. The developed 3D IPMC transducer is used to enclose a section of optical fiber, thereby allowing electronic directional control of conducted laser light. This could be useful in applications such as microendoscopic ocular surgery. The fabricated device with the IPMC actuator
Abstract This paper presents an embedded sensing system for precisely measuring acceleration and ... more Abstract This paper presents an embedded sensing system for precisely measuring acceleration and temperature of interest points on a ball screw structure and diagnosis of different ball-screw preloads based on processing acquired signals with further classification using the support vector machine (SVM) method. The sensing system consists of a sensing unit and a hardware signal-processing unit. The core sensors utilize a MEMS-type accelerometer and glass-type SMD PT-100, integrated into a 1 cm×1 cm circuit board and packaged with a metal housing sensing unit with a dimension less than 1.5 cm 3 . The sensing unit is embedded into the screw nut of a designed preload-adjustable ball screw, installed on a computer-controlled single-axis stage for testing. Acquired signals with good noise immunity in an industrial environment are achieved through the developed hardware signal-processing unit. Measured acceleration and temperature data for different ball-screw preload levels based on time and frequency domain analysis are performed. The results demonstrate achieving diagnosis of a ball-screw preload within 20 s, with a preload level classification reaching nearly 100%. The developed sensing system and analysis method can apply to monitor ball-screw health and would be very useful in industrial applications.
... pared with solar or electromagnetic generators, design of piezoelectric microgenerators requi... more ... pared with solar or electromagnetic generators, design of piezoelectric microgenerators requires relatively ... SP, White NM (2001) Towards a piezoelectric vibration-powered microgenerator. ... NM, Glynne-Jones P, Beeby SP (2001) A novel thick-film piezoelectric micro-generator. ...
This paper proposes a tunable-focus liquid lens implemented with a simple cylindrical container s... more This paper proposes a tunable-focus liquid lens implemented with a simple cylindrical container structure and liquid as the lens material. The cylindrical container was constructed using a Pb [Zr(0.52)Ti(0.48)]O(3) (PZT) ring transducer and a polydimethylsiloxane membrane that was attached to a flat side of the transducer. The free surface of the liquid in the cylindrical container can be driven as a static-like convex lens with different curvatures because the higher-order harmonic resonance of the PZT transducer was electrically controlled. Based on a capillary-force-dominant design, the activated liquid lens maintained surface curvature in an arbitrary orientation without a gravitational effect. Profiles of the liquid lenses were characterized with the driving voltages of the transducer ranging from 12 to 60 V peak-to-peak (Vpp) at a resonant frequency of 460 kHz. The temperature effects on the lenses caused by the continuous operation of the transducer were measured. Images showed the various curvatures of the lenses with a range of actuation voltages. A change in focal length of eight times (5.72 to 46.03 cm) was demonstrated within the 10 Vpp variation of the driving voltage. For the characterized liquid lenses, the distortion was less than 2%, and the modulation transfer function reached 63 line pairs per mm (lp/mm) using ZEMAX analysis.
Page 1. Micropump based on PZT unimorph and one-way parylene valves This article has been downloa... more Page 1. Micropump based on PZT unimorph and one-way parylene valves This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2004 J. Micromech. Microeng. 14 429 (http://iopscience.iop.org/0960-1317/14/4/001) ...
The present paper examined a novel micromachined column structured Ion Polymer Metal Composite (I... more The present paper examined a novel micromachined column structured Ion Polymer Metal Composite (IPMC) actuator with multidirectional control capability. The developed 4-electrode transducer enclosed a section of optical fiber, thereby allowing electronic directional control of conducted laser light. The fabricated device with IPMC actuator dimensions of 5 mm x 2 mm x 1 mm reached a maximum displacement of 400 μm when a square wave of 9 V was applied to the top-bottom electrode pair. Displacements in different directions and moving angles were characterized with side-side and top-right electrode pairs connected to the actuating signals. Furthermore, the generating moment per volt per second by the transducer was analyzed. The maximum value of approximately 200 μN*m/V/s was displayed when the device actuated with the side-side electrode pair. Controlling the developed IPMC actuator moved the laser beam in multiple directions. This device could be promising for biomedical applications such as microendoscopic ocular surgery.
We fabricated three piezoelectric components (PZT) that can produce ultrasonic waves with various... more We fabricated three piezoelectric components (PZT) that can produce ultrasonic waves with various generated power in order to improve the delivery of DNA molecule and polymer/DNA complexes into cells. Two cationic polymers (PEI and PDMAEMA) were interacted with DNA to form nano-scaled DNA/polymer complexes with/without the help of PZT devices. The application of PZT devices under optimal conditions helped to avoid cytotoxicity and greatly increased the transfection (DNA delivery) efficiency of these complexes in mammalian cells. The cytotoxicity and transfection efficiency were found to be correlated with the PZT-generated power, waveforms and duration of ultrasonic treatment. There was no observable cytotoxicity in our experimental models and, a maximum transfection efficiency 700% greater than that of polymer/DNA complexes without applying ultrasound was achieved. The transfection efficiency of plain polymer/DNA complexes (without PZT treatment) corresponded to a 630-fold increase in comparison to the naked DNA. The waveforms of generated ultrasound greatly influenced the transfection efficiency, while cytotoxicity was not significantly affected. This means that, for optimal DNA delivery, duration of the peak voltage (Vmax/Div) also plays a role. In addition, the generated waves from PZT do not cause dissociation of polymer/DNA complexes or a change in the particle sizes of these complexes. In conclusion, these results suggest that the operation of PZT devices can be a tunable/safe way to greatly improve DNA delivery for gene therapy.
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