mb-microtec produces glow sticks that light up for years without electricity by using Tritium. Cockpit displays, weapon sights, or watches are designed to glow in the dark without electricity. How is this possible? With Tritium, a weakly radioactive gas. mb-microtec, a company that employs around 100 people in Niederwangen, leads the world in this technology.
For the small glow lights, glass tubes are filled with Tritium gas. The thinnest tubes are just 0.3 millimeters thick. The interior has a diameter of 0.1 millimeters: about the thickness of a hair. The tubes are coated with zinc sulfide. This layer causes electrons emitted by the Tritium to glow for decades.
In production, employees are busy filling glass tubes with Tritium gas and manually sealing them with a flame. "The training for this challenging work takes a year," says Roger Siegenthaler (50), the CEO of mb-microtec.
The glass tubes are cut to the desired length using laser equipment. The shortest measure 2 millimeters. Besides round, angular shapes and almost all colors are possible.
Is Tritium gas dangerous? "It is a radioactive gas," Siegenthaler admits, "but a weakly radioactive one, a so-called beta emitter, which is completely shielded by the glass and cannot penetrate the skin."
Siegenthaler makes the following comparison regarding radiation danger: Even if one were to inhale all the Tritium gas in the micro-lights of a watch, one would only absorb a radiation dose equivalent to eating a banana every two days for a year. This is because bananas contain a radioactive potassium isotope.
mb-microtec sources its Tritium gas from Canada, where it is produced in certain nuclear power plants (heavy water reactors). Although it is very precious, some waste cannot be avoided in the production of lights, for example, in leftover pieces. These Tritium-containing wastes were previously welded into gas-tight cylinders and stored temporarily. The radiation from Tritium halves every 12 years – much faster than many other radioactive wastes from nuclear power plants.
How the precious Tritium could be recovered from the leftover pieces and returned lights has long been a concern for the company. After intensive planning, a unique recycling plant could be put into operation, says Siegenthaler. It works in principle like sewage treatment: The Tritium is filtered and can be fully reused.
The quality is identical to that of purchased Tritium. "Many companies worldwide have failed at such projects; we have succeeded," says Siegenthaler.
Because of the Tritium, the company is supervised by the Federal Office of Public Health and the accident insurance Suva. To prevent anything from escaping, there is negative pressure in the building. Anyone entering or exiting must pass through an airlock. The radiation is measured. Generators ensure an uninterrupted power supply. And specific requirements also apply for fire, earthquake, and burglary protection. This explains why the company's two-story new building completed in 2018 cost 23 million Swiss Francs.
mb-microtec produces 15 million Tritium gas lights per year. They are supplied to customers worldwide in the security and automotive industries, in aerospace, and the watch industry.
Watches are also sold by the company under the brand name Traser. Around 30,000 units were sold in previous years. In 2022, just over 15,000 watches could be sold, also because the important Russian market could no longer be supplied due to war sanctions. Moreover, the company suffers from the effects of high inflation in various markets. Detailed business figures are not published.
Roger Siegenthaler came from the pharmaceutical company Roche in 2010. He initiated a forward strategy. This was made possible by the board of directors and the owner family Thüler. These are the descendants of Oskar Thüler, who first succeeded in making Tritium glass tubes glow. In 1969, his efforts led to the founding of MB-Microtec. MB refers to Merz+Benteli, the company founded by Oskar Thüler's father-in-law Walter Merz with Albert Benteli, known primarily for the adhesive Cementit.