A chip to measure vacuums

Vacuums are a vital part of the processes - such as freeze-drying - used to make and preserve countless everyday items and must be measured with precision. An EPFL spin-off, Hexisense, is bringing to market a gallium nitride-based chip that can measure the quantity of certain gas molecules cheaply and with unrivalled precision. What do a mirror, a cup of yogurt, an electric car battery and an LED lightbulb have in common? Their production processes all require a vacuum, i.e. an environment in which gas molecules are removed. Usually, when the last drop has been poured from a bottle, the bottle is considered empty. Physically, however, it remains full of gas. When a vacuum is required, suction pumps leave a varying amount of gas depending on the process used. A vacuum is therefore assessed on the basis of pressure exerted by the number of molecules that remain in the container.