Christmas goes digital: why mini Bosch components will feature in so many gifts this Christmas

Reutlingen, Germany – This year once again, the gifts under the Christmas tree will be emitting beeps, buzzes, and radio waves: according to Bitkom, some 70 percent of Germans will be giving digital gifts. This could be a smart watch, a game console, or of course a cell phone. This also means that Bosch will figure prominently under people’s Christmas trees, even though few may realize it. There’s at least one Bosch MEMS sensor in more than half the smartphones on the planet, and five of them on average in every new car. And there are millions more in drones, game consoles, fitness wristbands, and vacuum-cleaning robots. Bosch has produced more than ten billion of these miniature sensors in its wafer fab at Reutlingen, 40 kilometers south of Stuttgart, since 1995. “MEMS sensors are the building blocks of the connected world. They endow everyday objects with sensory perception and connect them with the internet,” says Jens Fabrowsky, member of the executive management of the Automotive Electronics division at Robert Bosch GmbH. With the number of connected devices rising fast – Gartner expects the global count to come to 20 billion by 2020 – MEMS sensors are sure to become chip-sized superheroes that we simply cannot do without.

MEMS sensors measure the world and teach electronic systems how to see, feel, and smell. They turn a simple cell phone into a smartphone that takes sharp pictures and navigates on the street and over multiple stories in buildings.

Jens Fabrowsky, member of the executive management of the Automotive Electronics division at Robert Bosch GmbH

Ten billion sensory organs

Rectangular or square and smaller than a pinhead at between one and four millimeters tall, these components are not easily seen. But however unremarkable MEMS sensors may seem at first glance, these mighty mites are the stars and polymaths of the connected world. “MEMS sensors measure the world and teach electronic systems how to see, feel, and smell. They turn a simple cell phone into a smartphone that takes sharp pictures and navigates on the street and over multiple stories in buildings,” Fabrowsky says. With the benefit of MEMS sensors, drones glide smoothly and can be controlled precisely even in winds. Installed in fitness trackers and smart watches, they count steps, stairs, and calories. These diminutive sensors’ fine-tuned receptors measure temperature, air pressure, humidity, and even air quality. They allow indoor air-conditioning and ventilation systems to be controlled more efficiently and, when office meetings drag on, they can trigger smartphone reminders that it is time for some fresh air. The first MEMS sensors developed nearly 25 years ago were not meant for smart-home technology or consumer electronics; they were destined for cars. These perceptive miniatures furnish data to the control units about when the car brakes or accelerates, as well as about the direction the car is traveling. The ESP electronic stability program uses this information to keep cars, trucks, and even motorcycles safely on track and in their lanes. Moreover, the GPS never loses sight of its destination, even if its signal is temporarily interrupted.

What exactly are MEMS sensors?

Microelectromechanical systems, or MEMS for short, are a combination of electronic and mechanical hardware. Every MEMS sensor consists of tiny silicon structures that are machined into a silicon wafer with a special type of etching process. For example, under a microscope, an acceleration sensor’s structures look like gossamer combs arranged in opposing and interlocking patterns. Some of these fine comb-like structures measure a mere four micrometers across – that is just a tenth the size of an ant’s leg. The force of a car accelerating or braking squeezes these combs. This changes the electrical voltage between the individual teeth, transforming a mechanical force into an electrical signal. A control unit interprets this signal and processes it further as a digital value. Bosch developed the manufacturing process behind MEMS technology nearly 25 years ago. It still forms the basis of today’s production runs, which take up to 14 weeks and entail several hundred steps. These tiny sensors are manufactured under exacting cleanroom conditions, as even the smallest airborne particles would disrupt their production. One cubic foot of air – that is about 30 liters – may contain no more than one particle weighing half a microgram. To put this into perspective, that equates to a cherry pit in Lake Constance – or 360 million bathtubs.