A Biocompatible Low Temperature Co‐fired Ceramic Substrate for Biosensors

Abstract

Low temperature co‐fired ceramics (LTCC) are widely utilized in the fabrication of compact, three dimensional, and highly integrated microelectronic components. Typical applications include military and mobile electronics applications requiring custom, hermetic, and/or high reliability packaging. These characteristics make LTCC attractive for use in microfluidic and biomedical application. However, commercial LTCC systems are not designed for biomedical applications and have unknown cytocompatibility. In the current work, an LTCC tape has been developed starting with materials of known composition and biocompatibility, a commercially available lime silicate glass and alumina. Tapes achieve high density for sintering temperatures compatible with LTCC processing (850 < T < 1000°C). The LTCC also exhibits low dielectric constant (K = 9.3) and dielectric loss (tan d < 0.005). A commercial gold electrode paste has also been co‐fired with the LTCC, with no delamination, cracks nor camber observed. In vitro biocompatibility was subsequently evaluated using human umbilical vein endothelial cells (HUVECs). HUVECs are observed to attach and spread on fibronectin‐coated LTCC substrates, and also in the leachate obtained by soaking LTCC in cell medium for 7 days. These results establish that the developed LTCC material is biocompatible and suitable for in vitro applications utilizing live cells.