This paper presents the design,fabrication,and characterization of a real-time voltage-tunable terahertz metamaterial based on microelectromechanical systems and broadside-coupled split-ring resonators.In our metamate...This paper presents the design,fabrication,and characterization of a real-time voltage-tunable terahertz metamaterial based on microelectromechanical systems and broadside-coupled split-ring resonators.In our metamaterial,the magnetic and electric interactions between the coupled resonators are modulated by a comb-drive actuator,which provides continuous lateral shifting between the coupled resonators by up to 20μm.For these strongly coupled split-ring resonators,both a symmetric mode and an anti-symmetric mode are observed.With increasing lateral shift,the electromagnetic interactions between the split-ring resonators weaken,resulting in frequency shifting of the resonant modes.Over the entire lateral shift range,the symmetric mode blueshifts by~60 GHz,and the anti-symmetric mode redshifts by~50 GHz.The amplitude of the transmission at 1.03 THz is modulated by 74%;moreover,a 180°phase shift is achieved at 1.08 THz.Our tunable metamaterial device has myriad potential applications,including terahertz spatial light modulation,phase modulation,and chemical sensing.Furthermore,the scheme that we have implemented can be scaled to operate at other frequencies,thereby enabling a wide range of distinct applications.展开更多
A comb-drive actuator for lateral movement of over 100μm under low driving voltage is designed. Side stability is analyzed to improve the performance of the actuator. According to the analysis,a comb-drive actuator w...A comb-drive actuator for lateral movement of over 100μm under low driving voltage is designed. Side stability is analyzed to improve the performance of the actuator. According to the analysis,a comb-drive actuator with small comb gap,high-stiffness-ratio prebent suspension beams, non-initial overlap, and linear-engaged-length comb teeth is proposed and the parameters of the actuator are derived. Experiments indicate that the actuator resonates at 573Hz with a Q factor of 35.88 and reaches a maximum displacement of over 100μm at a driving voltage of 7IV,which fulfills the design requirements and matches the analytical value to within 2.1%.展开更多
An integrated micro positioning xy-stage with a 2mm × 2mm-area shuttle is fabricated for application in nano- meter-scale operation and nanometric positioning precision. It is mainly composed of a silicon-based x...An integrated micro positioning xy-stage with a 2mm × 2mm-area shuttle is fabricated for application in nano- meter-scale operation and nanometric positioning precision. It is mainly composed of a silicon-based xy-stage,electrostatics comb actuator,and a displacement sensor based on a vertical sidewall surface piezoresistor. They are all in a monolithic chip and developed using double-sided bulk-micromachining technology. The high-aspect-ratio comb-driven xy-stage is achieved by deep reactive ion etching （DRIE） in both sides of the wafer. The detecting piezoresistor is located at the vertical sidewall surface of the detecting beam to improve the sensitivity and displacement resolution of the piezoresistive sensors using the DRIE technology combined with the ion implantation technology. The experimental results verify the integrated micro positioning xy-stage design including the micro xy-stage, electrostatics comb actuator,and the vertical sidewall surface piezoresistor technique. The sensitivity of the fabricated piezoresistive sensors is better than 1.17mV/μm without amplification and the linearity is better than 0. 814%. Under 30V driving voltage, a ± 10vm single-axis displacement is measured without crosstalk and the resonant frequency is measured at 983Hz in air.展开更多
For operation and manipulation with nanometric positioning precision,an integrated micro nano-positioning xy-stage is developed,which is mainly composed of a silicon-based xy-stage,comb-driven actuator and displacemen...For operation and manipulation with nanometric positioning precision,an integrated micro nano-positioning xy-stage is developed,which is mainly composed of a silicon-based xy-stage,comb-driven actuator and displacement sensor.The high-aspect-ratio comb-driven xy-stage is achieved by deep reactive ion etching (DRIE) in both sides of wafer.The displacement sensor is mainly composed of four vertical sidewall surface piezoresistor connected to form a full Wheatstone bridge.A simple vertical sidewall surface piezoresistor process which improves on the basis of the conventional surface piezoresistor technique is proposed.The experimental results verify the integrated micro nano-positioning xy-stage including the vertical sidewall surface piezoresistor technique.The sensitivity of the fabricated piezoresistive sensors is better than 1.17 mV/μm without amplification and the linearity is better than 0.814%.Under 30 V driving voltage,a ±10 μm single-axis displacement is measured without crosstalk.The displacement resolution of the micro xy-stage is better than 10.8 nm.展开更多
A MEMS compressed period-tunable grating device with a wide tuning range has been designed, fabricated and characterized. To increase the tuning range, avoid instability with tuning and improve the performance, we pro...A MEMS compressed period-tunable grating device with a wide tuning range has been designed, fabricated and characterized. To increase the tuning range, avoid instability with tuning and improve the performance, we propose in this paper a period-tunable grating which is compressed by large-displacement comb actuators with tilted folded beams. The experimental results show that the designed grating device has a compression range of up to 144μm within 37 V driving voltage. The period of the grating can be adjusted continuously from 16 to 14 μm with a tuning range of 12.5%. The maximum tuning range of the first-order diffraction angle is 0.34° at 632.8 nm and the reflectivity of the grating is more than 92.6% in the mid-infrared region. The grating device can be fabricated by simple processes and finds applications in mid-infrared spectrometers.展开更多
This paper summarized and reviewed recent studies of micro transportation systems (MTS) in the MEMS (Micro Electro-Mechanical System) field. Micro transportation systems can be identified and classified into three cat...This paper summarized and reviewed recent studies of micro transportation systems (MTS) in the MEMS (Micro Electro-Mechanical System) field. Micro transportation systems can be identified and classified into three categories based on the contact types between the objects and the actuators (i.e. liquid-based, solid- based and air-bearing type). Their advantages and disadvantages were also analyzed and compared. The au- thors have proposed and developed three types of solid-based MTS utilizing electrostatic comb-drive actua- tors and ratchet mechanisms to drive the micro container in straight and curved paths. These MTSs have been fabricated with silicon-on-insulator (SOI)-MEMS technology and tested successfully. In the near future, MTSs can be applied in different fields such as medicine (to classify and test blood cells), in bioengineering (to capture, sort and combine bio-cells, DNA), or in micro robot systems.展开更多
基金We acknowledge the National Science Foundation under Grant No.ECCS-1309835In addition,we acknowledge support from DOE—Basic Energy Sciences under Grant No.DE-FG02-09ER46643.
文摘This paper presents the design,fabrication,and characterization of a real-time voltage-tunable terahertz metamaterial based on microelectromechanical systems and broadside-coupled split-ring resonators.In our metamaterial,the magnetic and electric interactions between the coupled resonators are modulated by a comb-drive actuator,which provides continuous lateral shifting between the coupled resonators by up to 20μm.For these strongly coupled split-ring resonators,both a symmetric mode and an anti-symmetric mode are observed.With increasing lateral shift,the electromagnetic interactions between the split-ring resonators weaken,resulting in frequency shifting of the resonant modes.Over the entire lateral shift range,the symmetric mode blueshifts by~60 GHz,and the anti-symmetric mode redshifts by~50 GHz.The amplitude of the transmission at 1.03 THz is modulated by 74%;moreover,a 180°phase shift is achieved at 1.08 THz.Our tunable metamaterial device has myriad potential applications,including terahertz spatial light modulation,phase modulation,and chemical sensing.Furthermore,the scheme that we have implemented can be scaled to operate at other frequencies,thereby enabling a wide range of distinct applications.
基金the State Key Development Program for Basic Research of China(No.2006CB30040)~~
文摘A comb-drive actuator for lateral movement of over 100μm under low driving voltage is designed. Side stability is analyzed to improve the performance of the actuator. According to the analysis,a comb-drive actuator with small comb gap,high-stiffness-ratio prebent suspension beams, non-initial overlap, and linear-engaged-length comb teeth is proposed and the parameters of the actuator are derived. Experiments indicate that the actuator resonates at 573Hz with a Q factor of 35.88 and reaches a maximum displacement of over 100μm at a driving voltage of 7IV,which fulfills the design requirements and matches the analytical value to within 2.1%.
文摘An integrated micro positioning xy-stage with a 2mm × 2mm-area shuttle is fabricated for application in nano- meter-scale operation and nanometric positioning precision. It is mainly composed of a silicon-based xy-stage,electrostatics comb actuator,and a displacement sensor based on a vertical sidewall surface piezoresistor. They are all in a monolithic chip and developed using double-sided bulk-micromachining technology. The high-aspect-ratio comb-driven xy-stage is achieved by deep reactive ion etching （DRIE） in both sides of the wafer. The detecting piezoresistor is located at the vertical sidewall surface of the detecting beam to improve the sensitivity and displacement resolution of the piezoresistive sensors using the DRIE technology combined with the ion implantation technology. The experimental results verify the integrated micro positioning xy-stage design including the micro xy-stage, electrostatics comb actuator,and the vertical sidewall surface piezoresistor technique. The sensitivity of the fabricated piezoresistive sensors is better than 1.17mV/μm without amplification and the linearity is better than 0. 814%. Under 30V driving voltage, a ± 10vm single-axis displacement is measured without crosstalk and the resonant frequency is measured at 983Hz in air.
基金Funded by the High Technology Research and Development Programme of China (2007AA04Z315)
文摘For operation and manipulation with nanometric positioning precision,an integrated micro nano-positioning xy-stage is developed,which is mainly composed of a silicon-based xy-stage,comb-driven actuator and displacement sensor.The high-aspect-ratio comb-driven xy-stage is achieved by deep reactive ion etching (DRIE) in both sides of wafer.The displacement sensor is mainly composed of four vertical sidewall surface piezoresistor connected to form a full Wheatstone bridge.A simple vertical sidewall surface piezoresistor process which improves on the basis of the conventional surface piezoresistor technique is proposed.The experimental results verify the integrated micro nano-positioning xy-stage including the vertical sidewall surface piezoresistor technique.The sensitivity of the fabricated piezoresistive sensors is better than 1.17 mV/μm without amplification and the linearity is better than 0.814%.Under 30 V driving voltage,a ±10 μm single-axis displacement is measured without crosstalk.The displacement resolution of the micro xy-stage is better than 10.8 nm.
基金Project supported by the State Key Development Program for Basic Research of China(No.2006CB30040)
文摘A MEMS compressed period-tunable grating device with a wide tuning range has been designed, fabricated and characterized. To increase the tuning range, avoid instability with tuning and improve the performance, we propose in this paper a period-tunable grating which is compressed by large-displacement comb actuators with tilted folded beams. The experimental results show that the designed grating device has a compression range of up to 144μm within 37 V driving voltage. The period of the grating can be adjusted continuously from 16 to 14 μm with a tuning range of 12.5%. The maximum tuning range of the first-order diffraction angle is 0.34° at 632.8 nm and the reflectivity of the grating is more than 92.6% in the mid-infrared region. The grating device can be fabricated by simple processes and finds applications in mid-infrared spectrometers.
文摘This paper summarized and reviewed recent studies of micro transportation systems (MTS) in the MEMS (Micro Electro-Mechanical System) field. Micro transportation systems can be identified and classified into three categories based on the contact types between the objects and the actuators (i.e. liquid-based, solid- based and air-bearing type). Their advantages and disadvantages were also analyzed and compared. The au- thors have proposed and developed three types of solid-based MTS utilizing electrostatic comb-drive actua- tors and ratchet mechanisms to drive the micro container in straight and curved paths. These MTSs have been fabricated with silicon-on-insulator (SOI)-MEMS technology and tested successfully. In the near future, MTSs can be applied in different fields such as medicine (to classify and test blood cells), in bioengineering (to capture, sort and combine bio-cells, DNA), or in micro robot systems.
