Magnetic sensors detect the presence, strength or direction of a magnetic field that is generated from a source (which could be the Earth’s magnetic field, permanent magnet, electric current, etc.). Magnetic sensors often detect other parameters based on changes or disturbances in magnetic fields, such as, for example, rotational speed, position, proximity, heading, etc. Silicon-based magnetic sensor technologies include Hall effect, anisotropic magetoresistive ( AMR), and giant magnetoresistance (GMR). High volume applications for Hall effect or anisotropic magnetoresistive ( AMR) magnetic sensors have included automotive applications (such as camshaft or crankshaft position or rotational speed sensing, ignition timing, wheel speed sensing in connection with anti-lock braking systems, transmission speed sensing, seat belt tension, etc.).
Magnetic sensors (for example, Hall effect sensors) are also used in varied applications, such as keyboards, encoders, electric motor control, current sensing, proximity sensing, etc. In the consumer electronics arena, magnetic sensors (for example, silicon Hall effect sensors) have been widely used in such applications as flip-cover cell phones. Moreover, Hall effect sensors and AMR sensors have, more recently, been finding opportunities for compassing and heading in GPS-equipped cell phones.
There are key needs for magnetic sensors with improved sensitivity, smaller size, lower power consumption, and greater compatibility with electronic systems. Magnetic sensors with such key enhancements have key opportunities to exploit and potentially disrupt new markets/applications, such as, for example, geophysical exploration, medical devices (such as, for instance, hearings aids, pacemakers, cardiac defibrillators), medical diagnostics, and fluid condition monitoring.
In geophysical exploration area, the established magnetometer technologies, although highly sensitive, are very expensive. Sufficiently sensitive, but considerably lower cost magnetic sensors can allow for more cost-effective and comprehensive detection for such applications as mineral detection or geophysical mapping.
There has been significant activity regarding using magnetic sensors and minuscule magnetic microtags or beads for efficient, streamlined detection of, analytes, proteins, viruses, etc., with potential in such applications as, for example, drug screening, bioassay detection, or point-of-care diagnostic systems. There are also opportunities for very sensitive magnetic field sensors in microfludics techniques that use encoded magnetic microtags for more molecular clinical diagnostics drug discovery applications.
Ultrasensitive magnetic field sensors and magnetic nanoparticles have potential to create biosensors that can produce results rapidly for medical detection, diagnostics, and/or treatment of, for example, heart disease or cancer.
There are also opportunities for smaller, low power magnetic sensors to gain wider usage in such medical devices as hearing aids, and for magnetic sensors with a smaller size, high reliability, and ease of manufacture to find wider use in implantable medical devices, such as pacemakers or implanted cardioverter defibrillators.
Moreover, magnetic sensors have potential, going forward, to cultivate applications in such areas as location/tracking of intrabody objects (such as, for example, catheters) or possibly in enabling more convenient glucose monitoring capable of warning of low and high blood sugar.
Magnetic sensors (i.e., Hall effect sensors) also have potential in continuous monitoring of fluid condition and/or metal debris monitoring in fluids.
Timing Devices, which are used to synchronize components, are an integral part of diverse devices that contain an IC or generate a radio signal, such as computer systems, consumer electronics (for example, mobile phones or other portable electronic devices), communications equipment, and other electronics devices or systems, including measurement equipment.
Typically, quartz crystals and quartz crystal oscillators (consisting of a quartz crystal resonator and an oscillation circuit) are to generate an output waveform at a specified frequency for timing. The crystal oscillator creates an electrical signal with a precise frequency. The frequency can be used to keep track of time, provide a clock signal for digital electronic circuits, or to stabilize frequencies for radio transmitters and receivers.
A quartz clock utilizes the piezoelectric property of the quartz crystal. When a quartz crystal vibrates, a difference in electric potential is produced between two of its faces. The crystal has a natural frequency of vibration that depends on its size and shape. If it is placed in an oscillating electric circuit having nearly the same frequency as the crystal, it is caused to vibrate at its natural frequency, and the frequency of the entire circuit becomes the same as the natural frequency of the crystal.
Quartz resonantors/oscillators have such advantages as high frequency stability, stability over temperature, the frequency dependence on temperature is low, and excellent processing ability. The use of photolithographic techniques are, moreover, enabling fabrication of smaller quartz crystals.
However, quartz crystal resonators/oscillators can have shortcomings, especially as electronics devices continue to become increasingly smaller. Quartz crystal resonators cannot be suitably or readily integrated onto silicon CMOS wafers, their cost can increase when their package volume decreases, and they are susceptible to performance degradation when subjected to severe levels of shock and vibration. Using mechanical processes to treat, cut, and shape the quartz crystal can be increasingly challenging with respect to, for example, producing high frequency crystal in smaller packages. Moreover, while photolithographic processes can enable production of smaller quartz crystals, MEMS (microelectromechanical systems) techniques can enable even smaller resonators to be created.
Moreover, MEMS resonators/oscillators (which essentially use a silicon mechanical vibrating beam for the resonator) can have other advantages over their quartz crystal counterparts, such as better shock and vibration characteristics, ability to be programmed to any frequency within a continuous frequency range (rather than requiring a separate quartz device for each frequency); the possibility of integrating the MEMS oscillator in a package or on a single chip with the silicon timing device could provide cost or form factor benefits; MEMS technology could be employed to fabricate multiple resonators on a single die to make system-on-a-chip timing chips; and the MEMS technology may facilitate building a range of different resonator shapes to achieve various properties, frequencies, or Q factors.
While MEMS resonators have had some performance challenges of their own in the past (such as limited temperature stability, thermal hysteresis, long-term stability, as well as the potential of contamination unless they are well-encapsulated), performance improvements have enabled MEMS-based timing devices to begin to make inroads against quartz crystal timing devices in, primarily, crystal oscillators with a MHz frequency output where the specifications for temperature stability can be easier to meet.
Moreover, there are opportunities for MEMS resonators/oscillators to begin to make inroads against quartz crystals in both lower performance applications for MEMS oscillators with a 32 kHz frequency output (such as, for example, standby clocking in cell phones) or higher performance applications (e.g., temperature compensated MHz frequency output oscillators for such applications as cell phones or GPS receivers).
It is important to know the condition of the oil used in equipment (including vehicles and industrial machinery and mechanical devices), since oil that loses its lubricity must be changed or it will become contaminated.
At present, sensors are not typically and widely used to directly and continuously measure the quality and condition of oil in automobiles, heavy trucks, or other types of vehicles or machinery. Sensors have tended to have certain limitations for on-board/on-line oil condition monitoring, such as not being able to provide the accuracy of a laboratory analysis; not being able to adequately monitor various key determinants of oil quality (such as, for example, total base number (TBN), total acid number (TAN), viscosity, or soot, water, or fuel contamination); or being susceptible to interference or contamination. It may require an integrated array of sensors to ideally and optimally address the various parameters involved in oil condition monitoring.
The use of a sensor that accurately, directly measures the condition and quality of oil in automobile engines, heavy truck engines, or in other types of equipment (such as in large, more expensive engines or in industrial machinery with sufficient accuracy and reliability would enable more efficient, less time consuming and less costly oil changes; reduce the need for oil maintenance and downtime; and safeguard against the possibility of enhanced environmental problems that can arise from degraded or contaminated oil, such as CO2 emissions or disposal of the oil filter.
For example, in automobiles (including higher-end types), algorithms in concert with other parameters (for example, engine speed, temperature) are used to determine when an oil or filter change is required. This indirect, inferred approach may not adequately determine when engine oil should be changed in vehicle under certain driving conditions. As automaker’s seek to continue to extend the time period between oil changes, and the cost of gasoline rises, very cost-effective and reliable on-board oil condition sensors can have greater opportunities in higher-end and eventually more standard types of vehicles.
Moreover, direct oil condition monitoring sensors with the requisite accuracy, robustness, and comprehensiveness could find opportunities in varied areas where there can be a significant penalty if the condition of the oil sufficiently degrades, such as larger, more expensive diesel engines or industrial equipment (to achieve condition based monitoring).
There are barriers to capturing opportunities in direct, continuous oil condition sensing. To have opportunities to make inroads in direct, on-line/on-board oil condition monitoring, likely requires patience, tenacity, and an oil condition sensing technology that can be trusted to provide highly reliable, accurate, comprehensive yet cost-effective oil condition monitoring of mobile or fixed equipment or machinery. There has been work underway on diverse types of oil condition sensing technologies that hold promise, for example, ultra-sensitive Hall-effect based sensors for viscosity measurement.
Technology constantly evolves, creating threats to existing products but also generating opportunities for savvy companies who can develop technology that is targeted at capturing new applications and markets. To be positioned to thrive rather than suffer in the face of inexorable technology development, companies must have the courage and insight to invest in new technology development and commercialization. More importantly, they need to aim their technology development and investment at the most promising, significant, and realistic applications.
For example, in the MEMS and sensor industries that I have followed for some time, it is evident that companies who developed and commercialized MEMS-based devices for specific evolving and expanding application areas early on (who started their business around the early to mid-80s or before) became well positioned to initially capitalize on the expanded opportunities for silicon-based pressure sensors and accelerometers in such applications areas as vehicles (e.g., manifold absolute pressure sensors, airbag accelerometers, and later on, occupant safety sensors, tire pressure sensors, vehicle stability control sensors, etc.), medical (such as blood pressure sensors), industrial (pressure transmitters), aerospace (for example, inertial sensing) and so on. Many of the early MEMS sensor start-ups, such as NovaSensor, SenSym, IC Sensors, etc. were positioned to attract funding and acquisition opportunities.
MEMS inertial sensors (accelerometers and gyros) are also finding opportunities, spearheaded, for example, by the need for lower power, smaller, more cost-effective, readily integrated, and versatile accelerometers and gyros in consumer electronics devices. Younger, innovative and entrepreneurial developers and providers of MEMS-based inertial sensors for such applications as consumer electronics include, for example, Kionix (which was founded in 1993 and has been acquired by Rohm) and InvenSense (founded in 2003, which develops and provides MEMS gyros, including the achievement of an integrated dual-axis gyro).
Indeed, the development of MEMS-based gyros (angular rate sensors) has opened up key high-volume opportunities in such areas as mobile handsets and gaming (more intuitive, gesture-based motion control), digital cameras (image stabilization), and automotive (vehicle stability control/rollover detection/mitigation). MEMS technology (which essentially creates devices that are built into semiconductor chips using tools and techniques similar to those used in the integrated circuit industry) enables sensors and other devices (such as, for example, oscillators for timing in a plethora of applications, including consumer electronics) to have key opportunities to disrupt incumbent technologies, due to such benefits afforded by MEMS technology as greater miniaturization and form factor flexibility, reduced power consumption, ease of integration with other electronic components, and potential to be economically produced in very high volumes.
MEMS technology dovetails well with the ongoing trend toward ever smaller, lower power, and more integrated devices and electronic systems in a broad range of applications. In addition to the earlier MEMS devices that have found widespread use in the marketplace (such as MEMS pressure sensors, accelerometers, and, subsequently MEMS gyro sensors), a wide range of MEMS-based devices have, or are finding, opportunities in the marketplace going forward, including, for example, MEMS-based infrared thermopiles (which are widely used in such applications as ear thermometry, automotive climate control, air conditioners, microwave ovens, etc.); MEMS gas sensors for such applications as air quality monitoring or homeland security); MEMS microphones; MEMS magnetometers (for such applications as, for example, homeland security/defense, navigation or compassing, geological mineral detection, automotive, medical diagnostocs); microfluidics; MEMS biosensors or biological sensors (for such applications as DNA detection, drug delivery systems; etc.).
The key to the success of advanced, potentially disruptive technology (such as MEMS-based devices) rests on having access to very valid, unbiased information about the realistic opportunities and threats for new technologies and data about the most promising and accessible key markets/applications for such technologies.
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