High-sensitivity InSb thin-film micro-Hall sensor arrays for simultaneous multiple detection of magnetic beads for biomedical applications

An InSb thin-film linear micro-Hall sensor array of eight sensors, each with a sensitivity of 10 nT/Hz/sup 1/2/ was developed for biomedical applications. The individual Hall sensors had an active area of 5 /spl mu/m/spl times/5 /spl mu/m and were separated by a distance of 5 /spl mu/m. A combination of these Hall devices and a magnetization system incorporating both dc and ac bias magnetic fields, enabled the simultaneous detection of multiple 2.8 /spl mu/m diameter superparamagnetic beads.