David Tolfree, science and technology writer
Electrically powered transport, particularly cars, is an essential element in reducing carbon emissions in the atmosphere. The production of electric cars by all major manufacturers is inextricably linked to the supply of sensors, of which microelectromechanical systems (MEMS) sensors represent about a third. They are microsystems that combine passive and active electronics, electrical and mechanical parts integrated onto a silicon substrate that includes data processing functions. Advanced integrated circuitry (IC) technologies are primarily used for their manufacture.
For many years, sensors have been integrated into the design and manufacture of vehicles. It is a classic example of how the combination of different technologies can produce a commercially successful end product1. Cars can have 100 or more sensors that monitor and serve as controllers for some drive parameters. The public acceptance of electric cars and the future development of autonomous cars will rely on the ultra-reliability (defined as almost zero tolerance to failure) of these sensors. Redundant fail-safe systems, similar to those used in aircraft, will be required for autonomous cars.
The global automotive MEMS sensors market size was valued at US$1.89 billion in 2020 and is projected to reach $5.03 billion by 2028, growing at a compound annual growth rate (CAGR) of 14.5 percent from 2021 to 20282. Sensors currently fitted to petrol-driven cars need to have extra and increased functionality for their use in electric cars. They are needed to monitor electric motor and battery performance, braking, exhaust emissions and road conditions, etc. This is to ensure that electric cars meet the more stringent environmental and safety regulations now in place in many countries. The growth in demand for electric cars, as well as the increasing needs of suppliers of 5G communications and smart IoT systems, is placing more and more pressure on the manufacturers of MEMS sensors.
The production of electric cars requires a continuous component supply chain. The recent global pandemic and the shortage of semiconductor fabs have caused serious disruption to the supply chains. All major semiconductor and vehicle companies are now increasing investment in new manufacturing facilities to meet the continued increase in demand. New manufacturing facilities take time to build and establish, which raises serious competition and supply issues between major manufacturers in different countries, particularly China and the US.
Europe and North America are currently the two largest markets for automotive MEMS sensors. However, the growth in the Asia-Pacific region led by China and India is now significant. The issue of the global shortage of semiconductors may affect these market growths.
Electric car manufacturers have a wide choice of suppliers for sensors, each having its product specialisation. The major manufacturers of MEMS sensors and their development are in Europe, Japan and North America. They include:
- Allego microsystems (US);
- Bosch (US);
- Denso (Japan);
- Hitachi (Japan);
- Honeywell (US);
- Infineon (Germany);
- InvenSense (US);
- Mega Chips (Japan);
- Murata Manufacturing (Japan);
- NXP Semiconductors (Netherlands);
- Panasonic (Japan);
- Qualcomm (US);
- Robert Bosch (Germany);
- STMicroelectronics (Europe); and
- Texas Instruments (US).
Sensors for autonomous cars have to provide more extensive data to enable full automated control. They are required to detect oncoming obstacles and monitor all drive functions at close and distant surroundings to ensure safe passage. To simulate human drivers requires a high degree of artificial intelligence (AI). Sensors that derive the data from cameras, infrared (IR), radio detection and ranging (radar), light detection and ranging (lidar), and ultrasonic systems are required to instigate immediate reactions to changing drive situations.
Cameras are commonly used sensor elements in cars, but since they provide massive amounts of data, digital processing has to be employed to produce informed intelligence to the cars’ control systems. The disadvantage of cameras is that they rely on good visibility so need to be backed up with IR and lidar systems. The integration of the data from these is required to provide the necessary intelligence to ensure safe automated control.
It is common practice to connect individual sensors into systems to create a more accurate and detailed digital representation of the car’s functions and its surrounding environment. In electric cars, this information is displayed on a screen located in a position for the driver to view.
The worldwide automotive industry is undergoing a revolution as petrol-driven cars are gradually phased out and replaced by electric and autonomous vehicles. It is generally estimated that in the next 20 years, 50 percent of all cars will be electric. New technologies, coupled with government environmental regulations, may reduce that timescale. The strong competition between MEMS sensor producers will stimulate sensor innovation amongst suppliers.
MEMS sensors are set to continue playing a major role in electric cars. The increasing number of other applications where such sensors are used means greater numbers will be produced, significantly reducing unit costs.
References1Tolfree, D. (2017). System integration. Commercial Micro Manufacturing (CMM), volume 10, issue 6.Available at: https://bit.ly/3kIRaGZ
2Verified Market Research (2021). Global automotive MEMS sensors market size by product (pressure sensor, accelerometer, gyroscope), by application (safety and chassis, powertrain, infotainment, body and convenience), by geographic scope and forecast [report]. Verified Market Research, p.202.Available at: https://bit.ly/3oBEhzS