According to the MEMS and Sensor Research Report of IHS iSuppli, pressure sensor will become the most sold MEMS device by 2014 due to the relatively high price and the expanding application in automobile, medical and industrial fields.
As the auto industry recovered strongly after the recession, pressure sensor sales rose 26 percent last year to $12.22 billion, ranking second among all MEMS devices. This year's growth will be moderate, with an expected 6 per cent increase and sales of $1.3 billion, but it is expected to grow at double-digit rates in 2012.
With steady expansion, pressure sensors will become the highest selling MEMS devices in three years, the ubiquitous accelerometer and increasingly popular gyroscope. Due to the different compensation level, the calibration and packaging types of bare chip, the average price of MEMS pressure sensor varies greatly at present. The value oriented industrial and medical applications vary from several dollars to tens of dollars, while the most professional ones for aircraft hydraulic system or flight data measurement are as high as hundreds of dollars, including in bad media Industrial application combination under temperature and pressure.
By 2015, MEMS pressure sensor sales will reach $1.97 billion, with a composite annual growth rate of 10% in 2010-2015, as shown.
MEMS pressure sensor has been widely used in many applications
MEMS pressure sensor is a kind of thin film element, which deforms under pressure. The strain can be measured by strain gauge (piezoresistive type sensing), or by capacitance sensing the change of distance between two surfaces. Both methods are very popular, and tire pressure monitoring system uses a relatively strong pressure resistance method.
The automotive industry is still the largest application area of MEMS pressure sensor, accounting for 72% of its sales, followed by 12% of medical electronics, 10% in industrial field, and 6% of the rest in consumer electronics and military aviation.
In the automotive field, engine management is its main application, including manifold air pressure sensor in gasoline engine and common rail pressure sensor in diesel vehicle, especially in Europe. In order to improve combustion, some organizations are also studying pressure sensors that can work in cylinders to better measure the exact proportion of various substances involved in chemical reactions and feed back the data to the engine management system.
Because of the bad working environment, the price of automobile sensor is much higher than that of consumer sensor. In addition, the automobile sensors need a long identification time, and these sensors must be able to work reliably for up to 15 years. Some sensors, such as brake or tire pressure sensors, are essential to vehicle safety.
A new application of MEMS pressure sensor in automobile is the pressure sensing of transmission system, which is usually used in automatic device, but also used in new double clutch transmission system. Bosch, a German manufacturer, recently entered the market and launched a MEMS solution that uses oil to protect silicon films to withstand up to 70 bar pressure. Bosch also brought great changes to MEMS pressure sensor a few years ago. At that time, porous silicon was used, which brought highly reliable MEMS devices, which have been used in the current side airbag and other applications.
In the medical market, pressure sensors are mainly used as disposable low-cost catheters for surgical operation. But they are also used in expensive equipment to sense pressure and differential flow in CPAC. These devices have great potential and may become implantable sensors after 2015. Implantable sensors can work without batteries and can be used for heart measurement and glaucoma monitoring.
In the industrial field, the main applications of MEMS pressure sensor include heating, ventilation and air conditioning (HVAC), horizontal surface measurement, various industrial processes and control applications. For example, in addition to precise altitude pressure measurement, aircraft uses sensors to monitor engines, flaps, and other components.
MEMS pressure sensors are not particularly hot in consumer and mobile devices
So far, MEMS pressure sensor is not widely used in consumer electronics and mobile, and its sales volume is less than $20million. But it has many applications, including weather stations, sports watches, bicycle computers, diving equipment and step count. It can also be used in white appliances, such as water level sensors used in energy-saving washing machines.
In the mobile field, there is no large-scale application so far. In the future, high-end smartphones may use pressure sensors as altimeters to support indoor location services, but there is no infrastructure for this. In the tablet field, pressure sensors have so far been used only to enable them to display local weather conditions.
Compared with the wide use of accelerometers and gyroscopes in consumer electronics and mobile, the application of pressure sensors in this field will be very limited in the next few years.