Silicone-based encapsulation of a cell culture measurement device under physiological conditions

Impedance measurement with interdigitated electrode structures (IDES) is suitable for monitoring concentration and proliferation of adherent biological cells [1]. In some applications [2] the sensor interface has to be operated in the humid environment where the cells are cultivated. There, the combination of the ambient humidity with ionic contaminations of the electronic components causes a drift in the sensor signals. We present an encapsulation based on polydimethylsiloxane (PDMS), a silicone, which reduces humidity-induced drift of the sensor signals to values clearly below 1%. Affection of the cell culture media or the cell culture by gas emission of the cured PDMS was not observed.