#microelectromechanical

[randomnightowl]

Micro Electromechanical Systems (MEMS)

http://www.mit.edu/~kardar/research/seminars/Casimir2010/talks/Harvard2017/Casimir.html

[evolving-science]

Implantable Microdevices: Connecting Biomaterials and Medicine

Implantable microelectromechanical systems (iMEMS) have a number of exciting applications for medicine in the future, including the delivery of drugs to treat certain localized cancers.

[evolving-science]

New Type of Gyroscope is Smaller Than Grain of Rice

A group of Caltech scientists has just created an optical gyroscope at the nano-scale. You wouldn't believe it if we said that this device is smaller than a grain of rice!

[get-knows]

New reservoir computer marks first-ever microelectromechanical neural network application A group of researchers reports the construction of the first reservoir computing device built with a microelectromechanical system.

[reportsandmarkets]

Microelectromechanical Systems Microphone Market share and Growth Report Forecast to 2017

Microelectromechanical Systems Microphone Market share and Growth Report Forecast to 2017

About: Microelectromechanical Systems Microphone Microelectromechanical Systems Microphones market is valued at USD XX million in   2016 and is expected to reach USD XX million by the end of 2022, growing at a CAGR of XX% between 2016 and 2022. Download Sample Pages of Given…

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[nagarae-blog]

MEMS microphone pancake The wafer of Taiwan can not be eaten for the factory

Global microelectromechanical (MEMS) The market of microphone strengthens rapidly, it is estimated global market scale will be up to 1,600 million in 2011, for this reason already many IDM big factories and MEMS design companies have put into market of MEMS microphone, continues the electron (Knowles) of the floor , Akustica design company join the intersection of MEMS and the intersection of microphone and battle field successively, Scotland the intersection of sound effect and the intersection of chip and loud factory Wolfson also claim to join MEMS microphone war situation, however, take the place of the factory in always substituting the worker Taiwan wafer for being proud with silicon wafer, but still seen up till now but can not wipe out the order of design company of MEMS microphone. The global MEMS microphone market scale will invite 600 million (the city suit well in the organization YoleDevelopment materials) alone in 2008 ,It is estimated that the market of global MEMS microphone would surge and increase to over 1,600 million until 2011, the market demand mainly comes from the notebook computer (NB) , mobile phone, digital camera (DSC) , handheld homing device, the intersection of bluetooth and earphone and the intersection of network and scene,etc., estimate to compound person who grow up, reach 43% every year 2006~2011 year, this also impels many manufacturers to step into the breach as another fell to put one's back into market of MEMS microphone. In fact, the player had already had much originally on market of MEMS microphone in the past, had included IDM large factory's Ya De promise (ADI) , fly, think Karl (Freescale) , purpose law is semi-conductive (STMicroelectronics) , Ling (Infineon) flies in Great Britain , Omron, and some MEMS microphone design companies such as floor electron, Akusticas,etc., but have many of big the intersection of factory and position blocking in succession already, have an optimistic view of the intersection of MEMS and microphone to account for whole the intersection of MEMS and the intersection of market and the intersection of output value and about 20% huge business opportunity future, Wolfson will also claim to step the market of foot MEMS microphone to the outside in the near future. Wolfson shows, invests MEMS microphone major cause, lies in for Wolfson, the microphone is that one is analogous to the chief in the whole sound effect products supply chain, Wolfson can have own a whole set of MEMS manufacturing technology and ownership of property (IP) intelligently in order to reach ,Purchase and combine Oligon in June of 2007, to customer, because it has 100% of the own technology, so, can design different products according to customer's demand whenever and wherever possible. On the other hand, and stability high, the intersection of MEMS and microphone of Wolfson adopt standard the intersection of CMOS and process for preparing for can let the intersection of products and quantity production, thus, it can give the standard the intersection of CMOS and wafer of process for preparing take the place of the factory under the order, however, up till now, no matter MEMS microphone design companies such as electron, Akustica or backward Wolfson,etc. of the floor, have not still chosen the wafer of Taiwan to produce MEMS microphone for it for the factory. According to relevant owner, the electron chooses Japan Sony wafer factory to take the place of its generation of engineering MEMS microphones at present in the building, but Akustia choose Singapore take the place of factory and Wolfson take a fancy to South Korea and the intersection of Singapore and the intersection of wafer and factory.

[richasn-blog]

Research of the excursive wireless sensor network

First, foreword The wireless sensor network, as the microelectromechanical, communication and three kinds of products whose technology combined together of sensor, have already become a research focus of computer and communication field. The application of the wireless sensor network has a bright future, can apply to fields such as military affairs, environmental test and predicting, health care, intellectual home furnishing,etc. extensively, with the deepening and ripe studying to the wireless sensor, the sensor network will be advanced up to each field of human life gradually. At present, the study on wireless sensor is directed primarily to the characteristic of the wireless sensor network with limited energy outside China, have proposed a lot of energy-conserving MAC agreements and route agreements,etc.. But most research is limited to all nodes of the sensor are resting situations, do not meet some's needs and move nodal application, for example monitor the life of the wild animal, follow the trail of the patient's heartbeat situation,etc., the node is always in constant sports, sample ability that can also widen the cyberspace of introducing and moving the node at the same time, for example employing and moving the node and collecting other resting and nodal data, as a kind of information collection trough. In the wireless sensor network, may lead to the fact the major cause why network energy wastes is as follows, transmitted information conflict and node receive and deal with needless data ' Crosstalk phenomenon) , excessively intercept idly and control message is too much, etc. The primary service on MAC sublayer is the access of the control channel reliably, try hard to reduce or reduce the above-mentioned energy to waste. So, the design of the MAC layer agreement has important meaning to energy efficient utilization of the wireless sensor network. This text has introduced two kinds of excursive wireless sensor networks, one is ordinary node moving type, one kind is agency node ' Or trunk node) Moving type, explained the research current situation of the two at the same time, in order to carry on further research and improvement to the excursive wireless sensor. Second, excursive wireless sensor network model On the basis of the moving and nodal function, divide the excursive wireless sensor network into two kinds: One kind is ordinary node moving type, one is the agent node (or trunk node) Moving type. Make an introduction and analyze to these two kinds of nodes separately below. 1,Ordinary node moving type This kind of network model has distributed structure, each nodal function is the same, not having the difference of mainly coordinating some and less important and nodal, similar to Flat Ad Hoc network node, such as Fig. 1 (a) . The node may diverge from the present network at any time for a certain reason, or enter the new network, on the issue that will bring a series of access: How to judge the node diverges from / enters a network; How the network adapts to the nodal change; How mutual among the nodes. To other mobile networks, for example cellular telephone or moving Ad Hoc network, many have well solved their excursive schemes already, but these schemes are not suitable for the wireless sensor network, because the wireless sensor network is the limited type network of the energy, must consider the question of the energy loss in design of the network protocol. There are two kinds of efficient MAC access protocols of energy directed against this kind of network model at present: MS-MAC [1 ] and MOBMAC [2 ], these two agreements are set up above SMAC [3 ] foundation of the agreement, consider node excursive access and energy consumption question that brings. MS-MAC has proposed the mechanism of a kind of fast established connection, namely judge according to signal change that receives that excursive, start and move and handle the mechanism while needing. In a situation that there is no node to move or move the node only moves in a invention forms a cluster, work according to SMAC mechanism; Pass through fictitiously while forming a cluster in the boundry as moving the node, will move node and its ambient node (generally jump the inner node two times) One piece of forming " The dynamic land " ,Such as Fig. 2, the node inside the country has been keeping the work pattern all the time dynamically, until the node moving the node and forming a cluster newly is being set up. This way can avoid that it sets up the connection and causes the break of communication to move the too late and new network of node. MOBMAC has offered the high-efficient and low delayed MAC layer of energy for moving the sensor network and inserted the mechanism, consider the node moves the Doppler effect brought, adopt the justification frame length method of the adaptation, reduce the packet dropping rate caused by Doppler effect. At the time when the signal channel characteristic is good, increase the frame length conveyed each time, in order to accelerate the transmission of information; At the time when the signal channel characteristic is bad, reduce the length of the frame. Reducing the frame length has two advantages: The shorter frame compares with length frame, required transmission energy should be low; It should be relatively small that sudden Improper probability happens in the shorter frame. Karl horse electric-wave filter prediction algorithms extensible to adopt MOBMAC according to now and signal channel characteristic before this, the intersection of frame and length and the intersection of agreement and expenses before this come, predict, take transmissive the intersection of frame and length while being the next, thus reduce energy consumption and reduce the delay. Relatively find through the experiment, MOBMAC compares with SMAC, can reduce 60% of the energy loss, reduces the delays of 25%. 2,Agent's node moving type Lang Tong proposes a kind of SENMA (Sensor Network with Mobile Agents) [4]Network model, such as Fig. 1(b) ,SENMA has two kinds of network nodes: Node of the sensor and moving the agent node. Low power consumption and low-cost sensor nodal handling capacity and traffic carrying capacity are limited, and move the agent the node is the powerful hardware unit, and can move in the whole sensor network. In SENMA network, moving the node does not need communicating with the node of the sensor constantly, only just work when needing data gathering or carrying on network maintenance. The maximum of network advantage complicated data processing, insert, deal with and data transmit transmit and the intersection of route and the intersection of person who maintain and work act for node come, finish, the energy of lightening the sensor network is born, the node of the sensor is that the energy is limited, moving nodal energy can be supplemented. Fig. 2 can find out agent's node moving network is in the advantage of the energy-conserving respect: ( 1) In SENMA, the node of the sensor and moving the agent to communicate, the signal spreads in the free space, knowing according to the relation of signal fading and transmission distance, the decline of the signal is proportional to the second power of distance in the free space. And the information among the network nodes of the rightimage spreads along the earth's surface, signal fading is proportional to the fourth power of distance, thus the signal propagates the transmitted power of required identical distance it is large. ( 2) Not needing the nodal store-and-forward data of the sensor in SENMA, there is little energy consumed on received information. ( 3) Information processing and network maintenance are gone on by the agent node, and SENMA is the single patchcord network, need, maintain the intersection of route and information and the intersection of adjoining joint and information, spend in control the intersection of energy and expenses on take little. SENMA utilizes the spread spectrum technique of the direct sequence on the physical layer, the MAC layer adopts chance type ALOHA to insert the mechanism [5 ] at random. Each one needs to send the machine format node and judging whether can be sent according to one's own sending probability in chance type ALOHA, this probability is directly proportional to with moving signal energy that the agent receives. If some node in present the intersection of time slot and transmission data, enter the intersection of sleep and state, wait to play for the moment the crack comes. The network architecture of SENMA has congenital energy-conserving advantages, but its chance type ALOHA could further reduce energy consumption and remain to be tested by experiment to insert the mechanism. U.S.A. Nice university has proposed " On the basis of predicting the static network implement method to move trunk node " [6]. Make use of movable trunk node to collect the data of the static sensor network, save the energy of every sensor effectively, through predicting the sports of the trunk node, shorten the time that the sensor monitors the signal channel of communication, thus reduce energy consumption, achieve the goal of lengthening the life cycle of the sensor network. But in cases node of the sensor has been disposed densely, have not put forward very good solution to the problem of how to solve contention of signal channel. EAR (eavesdrop and register, Eavesdrop-And-Register) which UCLA university puts forward The algorithm [7 ] can not be used for to the resting node and moved the node not offering interruptedly the service, but this kind of algorithm is only suitable for the body keep resting, and move around the node individually and have a plurality of resting and nodal networks. But this can do the appropriate modification to insert algorithms, in order to accord with agent's node moving network. For example, regard moving node as the node of agent not limited of energy. EAR algorithm can be solved and moved nodal connecting the problem with mutual fashionable information, remain improved place also at significance of energy, for example can can let the intersection of quantity and moving noding, controlling whole the intersection of access and course limited, thus reduce energy consumption of the periodic radio news of resting node,etc.. Third, conclusion Autogenous characteristic and various applied demands of wireless sensor network, make the traditional radio protocol very difficult to be suitable for the wireless sensor network, meanwhile, moved nodal leading-in, proposed the new challenge to media's access protocol of wireless sensor network. This text has explained some imaginations and agreements put forward toward excursive sensor network abroad in recent years, establish the foundation that it studied and improved further. At present, the study on excursive sensor network of China relatively lags behind, a lot of problems urgently to be solved exist, need going still one step further to further investigate. Source: http://www.eepw.com.cn/article/61239.htm