MEMS in Automotive and Consumer Electronics

Microelectromechanical systems (MEMS)-based sensors have been in existence for decades, achieving mass-market penetration in a few applications such as medical pressure sensors and airbag accelerometers. Despite these successes, MEMS sensors have been largely restricted to these few isolated cases. Driven by the automotive and consumer electronics vertical markets, this is expected to change during the next decade.

In May 2006, Nintendo and Analog Devices announced the incorporation of Analog Devices' ADXL330 iMEMS accelerometer into Nintendo's Wii console. The accelerometer helped Nintendo raise video gaming to a new level. The global sales of this product are expected to top 10 million units by the end of the year and Nintendo is battling to meet the overwhelming demand.

Similarly, Apple's iPhone uses an STMicroelectronics accelerometer to sense whether the iPhone is in a portrait or landscape position and to rotate the screen accordingly. The iPhone is certainly not the first mobile phone to use an accelerometer to improve user experience, but judging by the reactions on consumer forums and blogs it has brought the term MEMS to the average consumer.

While MEMS sensors also find uses in vertical markets such as healthcare, aerospace, and industrial it is the automotive and consumer electronics verticals that are expected to be the key drivers during the coming decade. A fierce scramble is already under way as suppliers fight to establish a dominant position in the consumer electronics market.

Automotive Market
The primary applications for MEMS sensors in the automotive industry are pressure and inertial sensing, with both segments expected to experience robust growth within the next ten years.

Tire pressure sensors. The U.S. Congress's introduction of the TREAD Act mandates tire pressure sensors for all vehicles, requiring the sensors to warn the driver of underinflated tires within 20 minutes of detection. This feature will be available on all 2008 model cars, minivans, trucks, and sports utility vehicles (SUVs) in the U.S. The European Union is currently working on a policy to mandate compulsory installation of tire pressure sensors on all automobiles and this ruling is expected in two to three years. This segment is expected to grow at a combined annual growth rate (CAGR) of 30.7% and generate revenues of $526.7 million in 2012.

Other pressure sensors. Frost & Sullivan forecasts the market for other pressure sensors in the automotive market to generate revenues in excess of $700 million in 2012. The unit growth rate of 12.8% is expected to be slightly tempered by the drop in unit price. Pressure sensors in this segment include those used for engine management, brake fluid pressure, and in the exhaust gas recirculation system. Implementation of the Euro emission norms (which apply strict caps to pollutant emissions from automobiles) in emerging economies is also expected to drive the acceptance of MEMS-based pressure sensors, as are escalating fuel prices that increase the sales of more fuel-efficient vehicles.

Inertial sensors. Automotive applications for accelerometers include airbags, roll over detection, electronic stability control, navigation, security systems, and active suspension. Gyroscopes are used in stability control systems, anti-rollover systems, and GPS navigation systems.

One of the key growth drivers for MEMS sensors in the automotive market will be the electronic stability control (ESC) systems segment. These systems use three sensors—a gyroscope, an accelerometer, and a steering angle sensor—to detect any discrepancy between the driver's intention and the vehicle's actual motion. In case of a variation, the system intervenes to control the vehicle.

Europe currently leads the global stability control systems market as these systems become standard in new vehicles in countries such as Germany, Sweden, and France. Other countries are expected to follow suit as car manufacturers, responding to both customer demand and competition, include ESC systems as a standard feature on most models. Again, the growth could be more explosive if the European Union passes a law mandating compulsory installation of these systems in each vehicle.

The U.S. market for ESC systems is being driven by two factors. First, the National Highway Traffic Safety Administration (NHTSA) is encouraging car manufacturers to adopt stability control systems and is exploring the option to make them mandatory. Second, car manufacturers are using safety for competitive advantage. Frost & Sullivan expects the global market for ESC systems to hit 34 million in 2012; this number could be reached earlier if regulations are passed mandating the compulsory installation of these systems.

Figure 1 shows the accelerometer market for airbags. This segment has reached maturity in the North American and West European markets and is experiencing steady growth in other areas of the world. In India and China, despite the lack of government mandates for the compulsory installation of airbags, safety is becoming one of the main product differentiators among vehicle manufacturers. Frost & Sullivan expects this segment to generate revenues of $263.3 million in 2012.


Figure 1. This automotive MEMS accelerometer market graph shows the unit shipment and revenue forecasts for airbag sensors (world), 2002–2012. All figures are rounded; the base year is 2005
Source: Frost & Sullivan

GPS systems that use MEMS gyroscopes for dead reckoning are used extensively in countries such as Japan where they are becoming a standard feature in every vehicle. The Japanese market for GPS navigation systems witnessed significant growth from 2002–2004 as leading automakers such as Toyota Motor Corp. introduced telematics systems and services, triggering an increase in sales. However, inadequate traffic infrastructure and the high cost of navigation systems are expected to restrain the growth of this market.

Consumer Electronics
Notebook computers. When a notebook is dropped, MEMS accelerometers protect a computer's hard disk by detecting the fall and signaling the hard drive to park its read head safely. To this end, companies such as IBM, Toshiba, and Apple have incorporated accelerometers into their higher-end notebook computer models. The trend toward larger-capacity hard disk drives incorporated into smaller products is forcing industry participants to consider accelerometers as a means of avoiding data loss.

Market drivers in this segment include a drop in the price of accelerometers, the need for product differentiation on the part of notebook manufacturers, and increased consumer awareness. Frost & Sullivan expects this segment to generate revenues of $202.3 million in 2012 (Figure 2).


Figure 2. Consumer electronics MEMS accelerometer market chart, showing unit shipment and revenue forecasts for computer notebooks (world), 2002–2012. All figures are rounded; the base year is 2005
Source: Frost & Sullivan

Mobile Phones. Mobile phones are increasingly used for more than just communication—they can also act as music players, digital cameras, and gaming devices. Mobile handset manufacturers are looking to add features to their devices to differentiate their products from those of the competition.

Accelerometers in mobile phones are used to provide image stability, shock detection, menu navigation, text scroll, gaming control, silent mode activation, and motion dialing, among others. For example, the Sony Ericsson W910i uses an accelerometer to change the tune when the user shakes the phone; a vibration lets the user know that the track has been changed.

Manufacturers such as Mitsubishi, Samsung, and LG have been incorporating accelerometers into their high-end phones for the past three or four years but these phones have been restricted to markets in Japan and South Korea. Recent developments, including the development of the iPhone, have changed this trend.

MEMS gyroscopes have the potential to add value to consumer electronics devices by providing image stabilization, pedestrian navigation, and improved user interfaces.

The consumer electronics market is not without challenges. With very short product life cycles, electronics manufacturers are consistently working to develop products that offer unique features. These suppliers often rely on sensor manufacturers to introduce the right solution to add the feature rather than supplying only the sensor. In this regard, sensor manufacturers need to work with the electronics OEM to help design and incorporate the sensor into the device.