MEMS Pirani Sensors for Plasma Sterilization Applications

Low pressure plasma sterilization has been developed as secure sterilization

methods and has already been put to practical use for medical equipment. Although the mechanisms are not yet fully understood, the following cellular inactivation mechanism has been reported: ultraviolet radiation in the far-ultraviolet and mid-ultraviolet range is capable of damaging nucleic acids (DNA, RNA) and proteins.

In order to produce such ultraviolet radiation the pressure of the gas mixture used

as plasma source should be well controlled in the range of 13 to 130 Pa.

We have developed Pirani sensors which can be used to control the pressure of

the gas mixture. The amplified response of a Pirani sensor to pressure variation is shown in the following figure. It can be seen from the figure that the controlled pressure locates the sensitive range of the Pirani sensor.