The  mobile phone has enjoyed exploiting the sensor world as  Google's recently launched Nexus  shows by boasting not only an accelerometer sensor; a proximity sensor, an ambient light sensor, but also a digital compass, not to mention the usual 5MP camera but with 2X digital zoon, autofocus and flash.

Hardware and components cost around $175 according an iSuppli teardown. and it is reported as selling for $529 in the US or $179 with a two year contract from T-Mobile.

And although customer forums have been filled with a cacophony  of gripes as  Google found itself unprepared to deal with the high service expectation customers who pay for the $529 smartphone, at least the sensors are blameless.

A 27-year-old database programmer in Long Branch, N.J, have complained of dropped calls, plodding download speeds and connectivity snags. “The hardware is great, but the software is a mess,” he said.

The other mobile phone sensor expert Synaptics, partnered with Texas Instruments, Immersion, TheAlloy, and The Astonishing Tribe has continued the sensor approach  with (left) Fuse.

This collaborative mobile phone concept, has integrated multiple interface technologies, including multi-touch capacitive sensing, haptic feedback, 3-D graphics, force, grip, and proximity sensing.

But for iSuppli Corp, it is not so much proximity sensors but the silicon magnetic sensor market that is on the boom which it estimates will reach $1.4bn in 2013 revenues, up from $821m in 2009. This equates to slightly more than 5bn magnetic sensor ICs and switches, up from about 2.8bn units in 2009.

“Magnetic sensors represent one of the most pervasive types of sensors sold today,” says iSuppli senior analyst, MEMS and sensorsRic, hard Dixon.

“Silicon sensors are outgunning competition from potentiometers, Reed switches and micro-switches by eliminating issues with wear, by incorporating electronics on-chip for more intelligence per area, on robustness, and on cost and size,” he adds. “Hall effect sensors ICs and switches largely dominate the silicon magnetic sensor IC market, but increasingly, AMR and also Giant Magneto-Resistance (GMR) sensors are used for high-performance applications.

“Devices are used in areas ranging from high-cost applications like industrial motors that require accurate knowledge of rotor position to control loads; to mid-priced automotive sensor ICs that measure rotation speed angle, and position; to low-cost consumer products. Because of this wide variety of uses and products, pricing for such sensor ranges from less than 10c for simple switches to several dollars for sophisticated programmable sensor integrated circuits (PSIC).”

Automotive applications drive sensor sales with body & powertrain segments. In automotive body alone, the number of magnetic sensors and switches will grow from 6.7 on average in 2008 to 9.4 in 2013.

Inexpensive switches are needed to indicate when a white goods door is shut, or a folding display phone, notebook PC or digital camera is open, or to adjust motors that help a deliver sharp, blur-free pictures. Linear sensors and switches are used to provide fluid levels in everything from drug delivery systems to automatic coffee dispensers found in the home.

Electronic compass market is hot
New product category, the electronic compass for GPS-equipped  mobile phones—emerged in 2009 and will accelerate  market opportunity for 3-axis silicon magnetometers measuring small magnetic fields out to 2013. This application, in addition to other sensors and switches in mobile phones, will help drive this category from just 10% of the magnetic sensor market in 2008 to 33% by 2013.

In 2009 Asahi Kasei Microsystems stole the top spot in magnetic sensor revenue from Allegro Microsystems, thanks to leadership in the fast-growing electronic compass market. Other major magnetic sensor players include Micronas, Infineon and NXP, emerging Sensitec and austriamicrosystems.

"Sensitec is an example of a company that is leveraging legacy Asymmetric Magneto-Resistance (AMR) technology, partly from an older IBM read-write head manufacturing plant, experiencing fast growth in these higher-value sensor applications,” says Dixon.

Fusion embeds controls in magnetic bearings
US company Synchrony Inc has miniaturised and embedded the control system for magnetic bearings, traditionally dozens of cables, processors and power amplifiers, into the housing of the magnets themselves.

This eliminates the need for extensive cables or separate cabinets and simplifies installation. The control system detects and then adjusts the position of the shaft about 15,000 times a second by redistributing the current to the electromagnets.

Synchrony’s new Fusion bearings,  have been installed on test motors at Baldor Electric. “When you hold the bearing in your hand,” he said, “you are also holding all of the electronics.” says William Pizzichil, engineering VP at Baldor, which makes electric motors.

Victor Iannello, Synchrony CEO says the bearings they replace typically had at least 40 wires connecting the electromagnets and sensors to a control cabinet. Now there is just a connection to the power supply, and an ethernet cable to each bearing so that information on vibration, for example, is available to devices monitoring the system.

In general, magnetic bearings have a higher initial price tag than the oil lubricated versions, but  because magnetic bearings eliminate other expense, they are ultimately cheaper. In an estimate for a pump system while the magnetic bearings would cost about $45,000 more than oil-lubricated ones,  the magnetic version saves all the capital costs of lubrication equipment, as well as the equipment installation and  maintainance cost.

Sensing for Canada's water mains infrastructure
In Canada,  Pressure Pipe Inspection Co offers a variety of "live sensing" inspections of water mains. One of its products, Sahara, consists of a tethered sensor inserted into a water main through a tap. Once inside, a small parachute at the tip opens up and uses the water flow to carry the sensor along a lengthy section of pipeline. As much as 15 metres above, a technician walks tracking the location of the sensor and listening for acoustic changes that signal leakage or other potential trouble spots.

Sahara can also be modified to carry a video camera, allowing  detailed visual inspection as far as one kilometre using a fibre-optic-lined tether. The camera system can spot everything from zebra mussels and lost valves to illegal taps (common in developing countries).

One of the company's more recent products is PipeDiver, a battery powered free-swimming device. It was designed to inspect large pre-stressed concrete pipes, including those used in wastewater systems. These pipes are wrapped with a reinforcing steel wire. The PipeDiver, once injected into an in-service pipeline, travels with the water flow, detecting highly stressed or broken wires in the concrete. A technician tracks the device's location from the surface.

PipeDiver can bend around corners, and even squeeze through butterfly valves, having flexible fins that keep it centred in the pipe. During a recent inspection in Mexico the device travelled a record 37 kilometres. Once at its destination, a net-like trap literally catches the PipeDiver and pulls it to the surface.

Inspection gives utilities better information about the infrastructure state to accurately target what gets fixed, and when. That also helps utilities reduce water loss identifying and tackling leaks much earlier. Losing less water means using less water-processing electricity, which also translates into savings

US infrastructure fatigue sensing
MATECH Corp expects its safety solution Electrochemical Fatigue Sensor (EFS) System (left) to significantly benefit from proposed increases in US federal  infrastructure development and maintenance projects of some $150bn to focus on job creation through infrastructure development projects such as highway and bridge construction.

The EFS system consists of an electrolyte, a sensor array and potentiostat for applying a constant polarizing voltage between the bridge/highway and sensor, as well as data collection and analysis software.

The current response from the sensor array, which consists of a crack measurement sensor and a reference sensor, are collected, analysed and compared with system software. An algorithm, specifically written for this system, automatically indicates the level of fatigue crack activity at the inspection location.

Bulk US Health sensing  goes wireless
According to a MobiHealthNews’ year-end report, of 15 VC investments announced in 2009, eleven were for wireless remote patient monitoring start-ups. Among them CardioMEMS developer of (right)  implantable wireless sensors that tracks cardiac output, blood pressure and heart rate which raised $22.1m; BiancaMed with wireless monitoring devices, including a motion sensor that detects heart rate and respiration raised $9.8m and Echo Therapeutics  a developer of a wireless blood glucose monitor for diabetics  got $3.6m.


DNA sensing in Rusia, pathogens in the US
Cooperation by several research institutes of Russian Academy of Sciences have resulted a new high-precision sensor for detecting substances that are hazardous and toxic for DNA. Russian researchers are using nano-sized constructions of DNA molecules, which change their optical properties, when interacting with toxic compounds.

The DNA molecules, immobilised in optically transparent, isotropic and chemically neutral gels and showing anomalous optical activity, are used as the integral biosensors. As a registering devices, the scientists suggest using a portable single-wave dichrometer, which converts optical signal of circular dichroism.

Next generations of the sensor will be smaller in size and cheaper than the prototype which has successfully passed first tests and has applications in various medical institutions, where direct detections of substances, toxic for DNA, are performed in liquids.

In the US biotechnology company, Mediomics used $775,000 from the Leonard Wood Institiute to develop a hand-held sensor based on fluorescence assay that can rapidly detect common pathogens such as E. coli or salmonella.

"Our original goal was that these could be used for soldiers in the field to test food or water samples quickly to see if they are contaminated," said Yie-Hwa Chang, professor of biochemistry at St. Louis University. The company teamed with St. Louis University and Washington University on the project.

Chang believes the device has applications beyond the military, such as in government testing and commercial food preparation and processing and hopes to get additional funding to build a marketable device.

Sensing power source from energy harvesting
One essential for the growth of sensing devices, especially in the "in vivo" approaches  is power. At the IEDM conference, IMEC research laboratory presented its piezoelectric energy harvesting device fabricated by MEMS technology that generates a record of 85μW electrical power from vibrations.

A wafer level packaging method was developed for robustness and the packaged MEMS-based harvester is used to power a wireless sensor node. Within the Holst Centre program on Micropower Generation and Storage, IMEC researchers developed a temperature sensor that can wirelessly transmit data in a fully autonomous way.

Micromachined vibrational energy harvesters operating in the frequency domain between 150 and 1000Hz are ideal devices to convert vibrations from machines, engines and other industrial appliances into electricity. Thanks to their smaller dimensions, the micromachined devices are the prefered candidates for powering miniaturized autonomous sensor nodes.

The harvester consists of a Si mass suspended on a beam with Aluminum Nitride (AlN) as piezoelectric material. By changing the beam and mass dimensions, the resonance frequency of the harvester can be designed for any value in the 150-1200Hz domain.

Not only the record power output, but also the use of AlN as piezoelectric layer, is a notable achievement. AlN has several advantages in terms of materials parameters and ease of processing compared to the commonly used PZT (Lead zirconate titanate). For example AlN can be deposited up to three times faster, while composition control is not an issue.

A wafer-scale process protects the piezoelectric devices by a vacuum package as it was shown that power output significantly increases with vacuum rather than atmospheric pressure packaging. In a three step process, glass covers are coated with an adhesive, and vacuum bonded on top and bottom of the processed wafer and diced.

The piezoelectric harvester was connected to a wireless temperature sensor, built from off shelf components. After power optimisation, the sensor consumption was reduced from 1.5mW to ±10μW, an improvement of three orders of magnitude.

Subjected to vibrations at 353Hz at 0.64g (indicating a realistic amplitude of the vibrations), the system generated sufficient power to measure the environmental temperature and transmit it to a base station with an interval of fifteen seconds proving the feasibility of building fully autonomous harvesters for industrial applications.such as tire-pressure monitoring and predictive maintenance of moving or rotating machine parts.

Harvesting power is definitely moving mainstream according to US analog expert Joshua Israelsohn and that can only heat up the sensing device market.

Sensor relocation in wireless mobile sensor networks
Wireless Sensor Networks (WSNs) have a  range of potential applications. Several research issues, which include energy-aware routing, sensor deployment problems, data aggregation, etc have been investigated.
Among this research, a key issue is to conserve usage of the limited battery energy of the sensor in the WSN to prolong its network lifetime for as long as possible and a movement-assisted sensor deployment is suggested in a cluster-based WSN, in which the sensor devices are capable of moving.

Based on mobility assumption for sensors, redundant sensors can relocate their positions to the low battery energy clusters to increase the overall network lifetime of the WSN, and a network optimisation problem is formulated.

This determines the optimum sensor relocation scheme so that the network lifetime value of the resulting network will be maximised. The NP-hardness result of the formulation was also conducted. A heuristic algorithm was proposed to give an approximate solution and the simulation results show that the proposed method performed better in prolonging the network lifetime of a WSN in practice, compared to other movement-assisted deployment algorithms.

Remoter power for inplantable sensing device
While currently inplant devices, such as cochlea or retinal implants, rely on inductive coupling, meaning the power source needs to be centimeters away, engineers at Brown University have now developed an implantable neural sensing chip powered by a radio source up to a meter away. The technology is similar to equipment used to power and read information from radio-frequency identification (RFID) tags.

So far, the technology has only been tested to measure neural activity in moths, but of course “the real challenges and application potential emerge in work with primates.” says Arto Nurmikko, professor of engineering at Brown University. Another small step in the diminishing of the border between people and products.


Building thin, flexible silicon electronics on silk substrates, researchers have made electronics that almost completely dissolve inside the body. So far the research group has demonstrated arrays of transistors made on thin films of silk. While electronics must usually be encased to protect them from the body, these electronics don't need protection, and the silk means the electronics conform to biological tissue. The silk melts away over time and the thin silicon circuits left behind don't cause irritation because they are just nanometers thick.

Whether the sensor is in your mobile, your dishwasher, the bridge you drive across, or even inside you - the offerings are becoming ubiquitous.