Magnetically actuated MEMS microlens scanner for in vivo medical imaging†

A magnetically actuated MEMS scanner with a microfabricated ferromagnetic nickel platform and thermosetting polydimethylsiloxane (PDMS) microlens is demonstrated. The device is driven by an external AC magnetic field, eliminating chip circuitry and thermal deformation from joule heating. The resonant frequency of 215.2 Hz and scanning angle of 23 of the scanner have been demonstrated. Experimental studies and optical modeling have shown that this microlens scanner achieves a scanning range of 125 mum when actuated by an external magnetic field of 22.2x10-3 Tesla flux density. The device has potential applications in in vivo medical imaging for minimally invasive diagnoses.