Optical imaging and patterning based on a magnetically controlled ferrofluid

A method comprising:

• positioning an active region on a substrate, the active region comprising a plurality of magnetic field generators;
• retaining a ferrofluid on the substrate adjacent to the active region, the ferrofluid forming a ferrofluid surface positioned within a range of a magnetic field generated by the plurality of magnetic field generators;
• activating one or more magnetic field generators to generate a magnetic field causing non-planar patterns to be formed at one or more regions on the ferrofluid surface;
• and
• receiving incident light on the surface of the ferrofluid including the one or more regions comprising the non-planar patterns, wherein an intensity of portions of the incident light reflected by the one or more regions comprising the non-planar patterns decreases to less than a threshold intensity required to expose an exposure surface that receives the reflected light.

An apparatus comprising:

• a substrate;
• an active region positioned adjacent the substrate and comprising a plurality of magnetic field generators;
• a ferrofluid positioned on the substrate adjacent the active region within a range of and interacting with the magnetic field of the plurality of magnetic field generators, the ferrofluid distributed across a plurality of ferrofluid regions, each magnetic field generator of the plurality of magnetic field generators aligned with a corresponding ferrofluid region;
• a control unit to apply a control signal to the active region, the control signal activating one or more magnetic field generators to generate a magnetic field that causes corresponding one or more ferrofluid regions to deform into one or more non-planar patterns;
• and
• an optical source to provide a collimated optical incident beam incident on the one or more non-planar patterns to produce a reflected beam having a reflection pattern based on the one or more non-planar patterns.