We describe a bioMEMS system for confining and electrically interfacing to single cells for long-term studies. The system comprises microvials that can be covered and uncovered by lids actuated by polypyrrole/gold hinges. Within each vial are integrated bio-amplifiers and/or other sensing circuits to form a biolab-on-a-chip. We have developed a process sequence for fabricating lidded microvials with actuated lids on CMOS die. Initial testing of these "cell clinics" with bovine aortic smooth muscle cells yields successful sensing of the extracellular action potentials from bovine aortic smooth muscle cells using a custom VLSI bioamplifier.