Development of radio-opaque silicon micro needles for medical diagnostics

In this paper, a method of fabricating radio opaque silicon micro needles for tissue labeling applications is reported. Cylindrical shaped micro needles ranging from 7 × 7 to 11 × 11 arrays with a pitch varying from 60 μm to 100μm are fabricated in silicon using a three step mask process. A backside cavity is generated under DRIE for filling the radiopaque material. Barium sulphate is filled in and a biocompatible sealing is provided to hold the radiopaque material inside. The fabricated needles provide a better contrast enhancement under x-ray imaging.