Applications of MEMS devices in nanosatellite

micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit（MIMU） , three micro complementary metal oxide semiconductor （CMOS）cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.

Research status and development trend of MEMS S&A devices: A review

MEMS Safety-and-Arming(S&A)device is the new generation of S&A device which integrates the mechanism of actuation and barrier.The features of minimized structure and easy integration make it to be the indispensable support to the development of weapon miniaturization,integration and intelligence.As a key component in the new generation weapon system,the sound development of MEMS S&A devices will have a significant impact on the future national defense system.Herein,the research status and development trend of MEMS S&A devices are introduced in this paper.From literature review on various MEMS S&A devices,it can be seen that the researches have evolved from individual components to system integration,and many prototypes have the potential for live-fire testing.Different driven principles and structures of the MEMS S&A devices are compared and summarized.At present,the MEMS S&A device can realize the mutual integration of the driving mechanism and the blocking mechanism on the micron level.In the future,with the establishment of new design criteria,MEMS S&A devices will develop from prototypes to practical applications,which will further promote the integration and intelligent of weapon systems.

Code mechanical solidification and verification in MEMS security devices

The virtual machine of code mechanism （VMCM） as a new concept for code mechanical solidification and verification is proposed and can be applied in MEMS （micro-electromechanical systems） security device for high consequence systems. Based on a study of the running condition of physical code mechanism, VMCM＇s configuration, ternary encoding method, running action and logic are derived. The cases of multi-level code mechanism are designed and verified with the VMCM method, showing that the presented method is effective.

Fabrication of Fuze Micro-electro-mechanical System Safety Device

Fuze micro-electro-mechanical system（MEMS） has become a popular subject in recent years.Studies have been done for the application of MEMS-based fuze safety and arm devices.The existing researches mainly focused on reducing the cost and volume of the fuze safety device.The reduction in volume allows more payload and,thus,makes small-caliber rounds more effective and the weapon system more affordable.At present,MEMS-based fuze safety devices are fabricated mainly by using deep reactive ion ething or LIGA technology,and the fabrication process research on the fuze MEMS safety device is in the exploring stage.In this paper,a new micro fabrication method of metal-based fuze MEMS safety device is presented based on ultra violet（UV）-LIGA technology.The method consists of SU-8 thick photoresist lithography process,micro electroforming process,no back plate growing process,and SU-8 photoresist sacrificial layer process.Three kinds of double-layer moveable metal devices have been fabricated on metal substrates directly with the method.Because UV-LIGA technology and no back plate growing technology are introduced,the production cycle is shortened and the cost is reduced.The smallest dimension of the devices is 40 μm,which meets the requirement of size.To evaluate the adhesion property between electroforming deposit layer and substrate qualitatively,the impact experiments have been done on the device samples.The experimental result shows that the samples are still in good condition and workable after undergoing impact pulses with 20 kg peak and 150 μs duration and completely met the requirement of strength.The presented fabrication method provides a new option for the development of MEMS fuze and is helpful for the fabrication of similar kinds of micro devices.

Chopper-modulated gas chromatography electroantennography enabled using high-temperature MEMS flow control device

We report the design,fabrication and characterization of a microelectromechanical systems(MEMS)flow control device for gas chromatography(GC)with the capability of sustaining high-temperature environments.We further demonstrate the use of this new device in a novel MEMS chopper-modulated gas chromatography-electroantennography(MEMS-GC-EAG)system to identify specific volatile organic compounds(VOCs)at extremely low concentrations.The device integrates four pneumatically actuated microvalves constructed via thermocompression bonding of the polyimide membrane between two glass substrates with microstructures.The overall size of the device is 32 mm×32 mm,and it is packaged in a 50 mm×50 mm aluminum housing that provides access to the fluidic connections and allows thermal control.The characterization reveals that each microvalve in the flow control chip provides an ON to OFF ratio as high as 1000:1.The device can operate reliably for more than 1 million switching cycles at a working temperature of 300℃.Using the MEMS-GC-EAG system,we demonstrate the successful detection of cis-11-hexadecenal with a concentration as low as 1 pg at a demodulation frequency of 2 Hz by using an antenna harvested from the male Helicoverpa Virescens moth.In addition,1μg of a green leafy volatile(GLV)is barely detected using the conventional GC-EAG,while MEMS-GC-EAG can readily detect the same amount of GLV,with an improvement in the signal-to-noise ratio(SNR)of~22 times.We expect that the flow control device presented in this report will allow researchers to explore new applications and make new discoveries in entomology and other fields that require high-temperature flow control at the microscale.