Methods are provided for making a multi-reservoir device comprising (i)
patterning one or more photoresist layers on a substrate; (ii) depositing
onto the substrate at least one metal layer by a sputtering process to
form a plurality of reservoir caps and conductive traces; (iii) removing
the photoresist layers using a liftoff process; (iv) forming a plurality
of reservoirs in the substrate; (v) loading each reservoir with reservoir
contents (such as a drug or sensor); and (vi) sealing each reservoir.
Optionally, the reservoir cap comprises a first conductive metal layer
coated with one or more protective noble metal films. To enhance the
resistance of the substrate (e.g., a silicon substrate) to etching in
vivo, the interior sidewalls of the reservoirs optionally can include a
protective coating (e.g., gold, platinum, carbon, silicon carbide,
silicon dioxide, and platinum silicide), or sidewalls comprising silicon
can be doped with boron or another impurity.