Micro Electro Mechanical Systems (MEMS) are components in which mechanical, electronic (and optical) components are combined. They are manufactured in sizes between 1 mm and 1 µm and using microelectronic materials and processes. Due to their small size, various physical effects gain or lose influence. For example, the surface-to-volume ratio increases with miniaturization, allowing for a higher rate of interaction with the environment.

In biosensor technology, MEMS can, among other things, be used as static sensors to detect environmental pollutants. In static MEMS, the interaction between the functional layer and analyte molecules is e.g.  detected by the bending of a membrane, which can be read by measuring the capacitance. Hydrogels can be used for this, which expand upon contact with the analyte.

 On the other hand, dynamic membrane sensors can also be used. With these sensors, the membrane is excited to oscillate by applying an alternating voltage. The addition of analytes leads to a change in the mass of the membrane, which can be determined by measuring the change in frequency. For such applications the membranes are e.g. functionalized using aptamers.