permanent magnet will prod uce higher fields than an elec-tromagn et, and can be further scale d to a smal ler size wi th-out a ny loss in fie ld stre ngth [13] . Minia turiza tion of
permanent magnet s also provides a n increa se in the
magnet ic field gradie nts while req uiring no elect rical power
supply an d no cu rrent leads. Finally, permanent magne ts
generat e no heat an d thus req uire no he at dissip ation. This
ability of ferromagn ets to provide high magnet ic fie ld gra-dients that can in turn spatia lly resol ve reson ant spins has
led Sidles to prop ose the magnet ic resonanc e force micro-scope (MR FM) [14] . In this instrument , a micr oscopic
magnet ic particle on a mechan ical can tilever acts as a
source of imag ing gradien t fields as well as a force gen era-tor on the sp ins whose magnetic reson ance the mechan ical
cantilever detect s [15] . Magneti c resonance image can be
obtaine d by mechani call y scan ning the tip in three dimen-sions over the sampl e.
In this arti cle, we focus on the magn etic resonan ce imag-ing protoco l that uses the interacti on between a sampl e and
the stra y fie lds from a geomet rically symm etric ferromag-netic sphere. We demonst rate that a two- or three-dim en-sional imag ing of a sample can be obtaine d without the
motion of the sampl e relat ive to the sphere. W e belie ve that