微机电系统的现状与展望

在过去20多年中,微机电系统(MEMS)已经从早期的技术开发、设备探索和实验室研究的阶段发展到当前的实际应用阶段,并逐渐扩展到许多新的研究和探索领域,MEMS已经成为21世纪最具潜力的研究领域之一。对MEMS进行了简要的介绍,包括MEMS应用,MEMS的市场情况,以及3种主要的MEMS微制造技术,即体微制造、面微制造和LIGA技术。最后,提出了MEMS将来研究和发展的趋势。     

业界动态

重庆大学"MEMS微型发电机系统"原理样机研制成功近日,由重庆大学承担的863计划MEMS专项课题“MEMS微型发电系统”原理样机通过了由自动化技术领域办公室组织的验收。该MEMS微型发电机的成功研制,将为微型能源与微传感器、微执行器、电路和微系统的一体化集成打下坚实的理论和技术基础。该样机具有微型化、高效能、长寿命、无需电池充电或燃料的更换、无废物输出、使用方便灵活、可批量生产等优点,在植入式装置、分布式传感器系统、无线通信、交通、玩具、航空航天、环境监测等领域具有广泛的应用前景与市场需求。读者服务卡编号021□…     

抓住机遇,全面推动我国MEMS的发展--访"863"MEMS重大专项总体组组长孙立宁教授

微机电系统 (MEMS )是多学科交叉融合的前言高科技技术 ,在工业、信息和通信、国防、航空航天、航海、医疗和生物工程、农业、环境和家庭服务等领域有着广阔的应用前景。为此本刊记者就国内外MEMS发展现状及趋势采访了863先进制造与自动化领域MEMS重大专项总体组组长孙立宁教授     

多轴微加速度传感器的进展

微加速度传感器是微型惯性组合测量系统的核心器件。随着MEMS技术的不断发展,单轴微加速度传感器的技术已日趋成熟,多轴微加速度传感器的研究正成为MEMS领域的热点。基于多轴微加速度传感器典型实例的介绍,评述了近年来该领域的进展,并就其未来的发展作了展望。     

微机电系统多场耦合仿真分析

在微电子机械系统(MEMS)研究和设计中,微系统数值仿真分析是一个重要研究领域．本文对MEMS中多种能量场耦合问题的各种数值仿真分析方法进行了综合评述．分析了该领域目前的研究现状并指出了其今后的发展方向。     

IMT携手CIT-China扩展中国MEMS产业链

<正>2014年9月9日,美国微机电系统制造商IMT与中国物联网研究发展中心(CIT-China)宣布达成了建立长期战略合作伙伴关系的意向。MEMS器件在汽车、智能手机等与人们日常生活相关的电子产品中随处可见,除此之外,在医疗领域的应用也越来越多,例如很多植入在人体内的传感器都是采用MEMS技术来制造。而IMT则是一家有14年经验的专注于MEMS工艺制造的代工厂,在MEMS制造领域,IMT积累了丰富的人才和经验,并且有多项MEMS制造方面的知识产权。     

MEMS压电-磁电复合式振动驱动微能源的设计

在单一效应的MEMS振动驱动微能源的基础上,提出了一种MEMS压电-磁电复合振动驱动微能源器件。该微能源由八悬臂梁-中心质量块结构和永磁铁两部分组成,环境振动使中心质量块振动,PZT压电敏感单元由于压电效应产生电势差;同时中心质量块上集成的高密度线圈切割磁感线产生感应电动势,将压电转换与磁电转换相结合把振动能转换为电能。建立了该结构的数学模型并用有限分析软件Ansys12.0对该器件进行力学特性分析,最后对加工出的微能源进行性能测试。测试结果表明,该微能源谐振频率为8 Hz,易与环境发生共振;在共振条件下,施加1 gn 的加速度,器件压电发电开路输出电压峰峰值达154 mV,磁电发电开路输出电压峰-峰值达8 mV,有望为无线传感网络节点提供稳定的能源。     

业界信息

行业动态汽车电子稳定程序(ESP)微传感器及系统取得阶段性成果先进制造领域863课题"汽车电子稳定程序(ESP)微传感器及系统"针对汽车电子应用需求,对MEMS陀螺仪和加速度传感器的结构进行了优化设计,开发出了基于体硅SOI和圆片级封装工艺的低成本MEMS微陀螺和微加速度计芯片,攻克了数字化陀螺仪电路设计和加速度计ASIC电路设计技术和预成型空腔塑封封装技术,研制出了自主知识产权的ESP用MEMS     

微机械薄膜热膨胀系数的测试结构

在微电子机械系统(MEMS)领域,薄膜的热膨胀系数对于微电子器件、MEMS器件,尤其是微热执行器的设计是一个十分重要的参数.本文详细介绍和分析了薄膜热膨胀系数的几种测试结构,对于微机械薄膜热膨胀系数在线测试结构的设计有一定的参考价值.     

MEMS国内外发展状况及我国MEMS发展战略的思考

一、前言 MEMS(Micro ElectroMechanical Systems,微机电系统)是多种学科交叉融合具有战略意义的前沿高技术,是未来的主导产业之一.MEMS以其微型化的优势,在汽车、电子、家电、机电等行业和军事领域有着极为广阔的应用前景.     

“中国微米纳米”一种低温制备的高灵敏度MEMS电容传声器

MEMS传声器是将声音信号转换成电信号的传感器.目前,MEMS传声器的研究主要涉及 MEMS电容传声器和MEMS压电传声器压阻传感器2种.与其它类型的MEMS传声器相比,MEMS电容传声器具有高灵敏度、高信噪比、频率响应平坦、低温度系数等突出的优点,被广泛使用在便携式设备、多媒体系统、助听器、信息采集等方面.设计和制备了一种高灵敏度的MEMS电容传声器,而且制备器件的工艺温度最高为300 ℃,可以兼容IC工艺.在本文,利用牺牲层的方法实现圆形振动薄膜,避免了方形薄膜存在的应力集中问题,并克服了干法制备圆形薄膜成本高的问题.基于聚酰亚胺材料,优化成膜工艺参数,实现低应力的圆形振动薄膜.通过设计防粘连结构,避免器件释放干燥过程中出现的薄膜粘连问题.根据振动膜应力为5 MPa,半径为2.5 mm,厚度为1 μm,电极半径为380 μm,间隙为1 μm的设计参数进行理论计算,该器件的电容在1 Pa 声压下的变化量为千分之一.与市场流通的MEMS传声器相比,高出约一个数量级,可被用于远场拾音,从信噪比极低的环境中拾取关键的声音信息.     

Five topologies of cantilever-based MEMS piezoelectric vibration energy harvesters: a numerical and experimental comparison

In the realm of MEMS piezoelectric vibration energy harvesters, cantilever-based designs are by far the most popular. For cantilever-based vibration energy harvesters, the active piezoelectric area near the clamped end is able to accumulate maximum strain-generated-electrical-charge, while the free end is used to house a proof mass to improve the power output without compromising the effective area of the piezoelectric generator since it experiences minimal strain anyway. However, despite while other contending designs do exist, this paper explores five selected micro-cantilever (MC) topologies, namely: a plain MC, a tapered MC, a lined MC, a holed MC and a coupled MC, in order to assess their relative performance as an energy harvester. Although a classical straight and plain MC offers the largest active piezoelectric area, alternative MC designs can potentially offer larger deflection and thus mechanical strain distribution for a given mechanical loading. Numerical simulation and experimental comparison of these 5 MCs (0.5 µm AlN on 10 µm Si) with the same practical dimensions of 500 µm and 2000 µm, suggest a cantilever with a coupled subsidiary cantilever yield the best power performance, closely followed by the classical plain cantilever topology.     

IC design of driving circuit of MEMS microrobot using pulse-type hardware neuron model

This paper presented a driving circuit which can output a driving waveform of the piezoelectric element impact-type actuator. The piezoelectric element impact-type actuator generates the rotational movement which is necessary to move the legs of the micro electro mechanical systems (MEMS) microrobot. The MEMS microrobot is made from silicon wafers fabricated by micro fabrication technology. The size of the fabricated MEMS microrobot is 4.0 mm × 4.6 mm × 3.6 mm. The driving circuit consists of a bare chip IC of the pulse-type hardware neuron model (P-HNM) and a peripheral circuit. P-HNM is an electrical oscillating model which has the same basic features of biological neurons. Therefore, P-HNM can output the driving waveform of the piezoelectric element impact-type actuator using electrical oscillation as biological neuron. As a result, we showed that the driving circuit can output the driving waveform of the piezoelectric element impact-type actuator without using any software programs or analog digital converters.     

圆片级低真空封装的MEMS压电振动能量收集器结构设计

MEMS低真空封装技术能为MEMS器件的可动部分提供低阻尼环境,降低能量损耗,有效提高器件的能量转换效率,具有重要的研究意义和应用前景,是MEMS技术的研究热点和难点。为了进一步提高MEMS压电振动能量收集器的输出性能,提出了圆片级低真空封装的共质量块MEMS压电悬臂梁阵列振动能量收集器新结构,通过有限元分析方法对器件结构参数进行了优化设计,在优化结构参数下仿真器件输出性能：在610 Hz、2 gn加速度下,器件的输出电压为8.88 V,输出功率为1220μW,能满足实际应用需求;根据器件结构设计了加工工艺流程,对低真空封装结构的实现和封装工艺探索具有重要意义。     

一种基于MEMS技术的压电微泵的研究

介绍了一种基于MEMS技术的压电微泵。该微泵利用聚二甲基硅氧烷(PDMS)作为泵膜,使用了一个主动阀和一个被动阀,并利用压电双晶片作为驱动部件。压电双晶片和PDMS泵膜的组合可以产生较大的泵腔体积改变和压缩比,显著降低了加工成本,并提高了成品率。对压电微泵的输出流量进行了测试,结果显示:电压、频率以及背压对流量均有显著影响。在100 V,25Hz的方波驱动下,该压电微泵的最大输出流量为458μL/m in,最大输出压力为6 kPa。     

Challenges in fabrication and testing of piezoelectric MEMS with a particular focus on energy harvesters

In this paper an overview of some of the challenges encountered in the fabrication and testing of MEMS-based piezoelectric devices is presented. All major steps involved in developing piezoelectric MEMS, with particular focus on energy harvesters, are examined in three main sections: Microfabrication, Packaging and Testing. Although the main focus of this paper are the challenges involved with vibration based piezoelectric energy harvesters, most of these challenges apply to other piezoelectric MEMS devices. Various techniques reported for each individual fabrication step are categorized to provide a summary of required information. This allows new researchers to estimate the overall fabrication process, available resources and equipment to prepare accordingly. In addition, challenges of each technique are pointed out explicitly with solutions from literature and our own research. These challenges are typically overlooked in results-based technical papers. Some of the technical solutions discussed were achieved in our experimental work. For other solutions found in literature, references are provided to address issues more in detail. Packaging piezoelectric energy harvesters can be especially challenging. Although a variety of packaging solutions exist for MEMS, these solutions are generic and must be adapted to fit the specific needs of the energy harvesters. This paper illustrates some packaging schemes that have been developed in our research to overcome these challenges. In addition, testing challenges and equipment requirements are discussed with sample results demonstrated. This article explores all fabrication steps, reviews literature, points out challenges and provides solutions with regard to developing piezoelectric MEMS.     

PZT压电薄膜在微传感器中的应用

锆钛酸铅压电材料(PZT)因具有优良的压电性能、热释电性能、铁电性能和介电性能而被广泛地应用在微电子机械系统(MEMS)中。基于微传感器,介绍了PZT薄膜,重点介绍了PZT薄膜在微传感器中的应用,并介绍了PZT薄膜微传感器的发展状况。     

A comparative study on MEMS piezoelectric microgenerators

The growing demand of wireless sensor networks has created the necessity of miniature, portable, long lasting and easily recharged sources of power. Traditional, hazardous batteries are rendered unacceptable and the viability of ‘green’ MEMS energy harvesters has become even more dominant. This paper reviews the state-of-the-art MEMS piezoelectric energy harvesters which promise a cleaner environment and eliminate the disposal issue of conventional batteries. Piezoelectric devices are the perfect candidate for implementation in micro generators as they are easily fabricated, are silicon compatible and demonstrate high efficiencies for mechanical to electrical energy conversion. The characteristic equations which govern the conversion of mechanical vibration to electrical power are described in this paper. The typical operating modes for MEMS piezoelectric energy cantilevers which are namely; d₃₁ and d₃₃ are also detailed. Criteria for optimum material suitable for MEMS energy scavengers to produce maximum power output are also outlined. Several MEMS energy harvesters which have been successfully fabricated and tested are also critically reviewed in this paper. Finally a comparison table highlighting the advantages and disadvantages of each work is presented.     

Wide bandgap semiconductor thin films for piezoelectric and piezoresistive MEMS sensors applied at high temperatures: an overview

The use of wide bandgap semiconductor thin films as sensing materials for micro-electrical–mechanical systems (MEMS) sensors has been the subject of much discussion in the academic and industrial communities. The motivation is that such materials are recognized as being suitable for extreme environment applications, namely: high temperatures, intense radiation and corrosive atmospheres. Among the wide bandgap semiconductor materials, aluminum nitride (AlN), zinc oxide (ZnO), diamond-like carbon (DLC) and silicon carbide (SiC) are highlighted due to their inherent sensing properties and compatibility with MEMS fabrication processes. Here we show an overview on the development technologies and applications of AlN, ZnO, DLC and SiC thin films in piezoelectric and piezoresistive MEMS sensors. Emphasis is placed on the influence of the temperature on the piezoelectric and piezoresistive properties of these films.