Bosch recently produced the
five-billionth MEMS sensor at its plant in Reutlingen, Germany. MEMS sensors
have been used in automobiles for 20 years, and in consumer electronics for 10
years. MEMS is an acronym for microelectromechanical system. According to a
press note from Bosch, MEMS sensors are the sensory organs of modern technical
systems. These sensors are small, robust, intelligent, and energy-efficient and
have a big impact because they save lives, increase driving comfort, help
conserve energy, and are an essential part of consumer electronics.
“MEMS sensors are a key
technology for the connected world,” says Dr. Dirk Hoheisel, member of the
board of management of Robert Bosch GmbH. “They deliver high performance, but
are also small, robust, and extremely cost-effective to manufacture in large
volumes,” he notes.
Bosch developed the underlying
semiconductor manufacturing process itself, and has been manufacturing the
sensors in large-scale production since 1995. “For 20 years, we have been
developing smart technology for a growing number of different areas with
real-life applications,” Hoheisel says. The first versions were used in motor
vehicles to detect pressure and acceleration. Now, 75 percent of all sensors
are used in consumer electronics. “Every second smartphone uses Bosch sensors,”
Hoheisel says. The company is the leading global manufacturer of MEMS sensors.
The start of large scale
production at Bosch in 1995 laid the foundation for modern technology. The
current portfolio comprises acceleration, yaw-rate, mass flow, pressure, and
environmental sensors, in addition to microphones. While it took 13 years to
manufacture the first billion MEMS sensors, the Bosch Automotive Electronics
division now manufactures the same quantity in less than one year at its production facility in Reutlingen, near
Stuttgart. This is the result of skyrocketing demand. More than four million
sensors are currently manufactured every day. These little helpers have an
average thickness of between just one and four millimeters. If the five billion
Bosch sensors were stacked on top of each other, the tower would be 12,000
kilometers tall; that is long enough to pass nearly all the way through the Earth,
which has a diameter of 12,742 kilometers.
cars, and smartphones – all need MEMS sensors
There are a wide range of uses
for MEMS sensors. The SMI700 sensor, for example, records a vehicle’s
rotational movements, lateral acceleration, and lean angle. It is at the heart
of the ESP anti-skid system, which keeps the car more safely on course during
critical situations. Another sensor, the SMP480, ensures quieter engine
operation and also optimizes the engine’s air-fuel mixture in changing environments.
This reduces fuel consumption, and provides for cleaner exhaust fumes.
In 2005, Bosch established the
wholly-owned subsidiary Bosch Sensortec GmbH, which offers a wide range of MEMS
sensors and solutions for applications in the consumer electronics sector,
including smartphones, tablets, and wearables. Inertial measurement units (IMU)
such as the BMI160 in the remote controls of game consoles are responsible for
gaming fun, for example. They transmit the movements of the player in real time
with extreme precision. The acceleration sensors in smartphones ensure that the
display changes orientation when the cellphone is turned. At the beginning of
2015, Bosch Sensortec unveiled another global first: the BME680. In one
housing, this environmental sensor measures air pressure, moisture levels,
ambient temperature, and, for the first time, air quality.
make non-electronic objects smart
The next major technological
revolution has already begun. In an increasingly connected world, things are learning
how to communicate. MEMS sensors are an important technological component that
is key to this process. Bosch Connected Devices and Solutions GmbH, established
in 2013, develops and markets connected, sensor-based devices, and custom
solutions for the internet of things. Programmed to be a smart technology and
fitted with a microcontroller, miniature battery, and a tiny radio chip, MEMS
sensors can process their readings and send them over the internet to a user’s
smartphone, for example.
It is essential for sensors to
be as small as possible, especially for smartphones, tablets, and similar
devices. The reason for this is that such devices are called on to perform ever
more functions – but have to do this in ever less available space. In consumer
electronics, MEMS sensors are less than one millimeter thick. Some of the
components inside sensors are a mere four micrometers (µm) thick – that is 17
times thinner than a human hair. These tiny parts are nonetheless robust and
very powerful. They also have to be extremely energy-efficient. An acceleration
sensor for the alarm system in a motor vehicle, for instance, has to be ready
for use at all times, yet draw as little power as possible from the car
battery. And in consumer electronics, low energy consumption is just as
important, since it helps a smartphone’s battery last as long as possible.