m-INK is a photonic crystal pigment in which 1~2 nm iron oxide magnetic nanoparticles form 70~120 nm particles.
Its reflective properties change according to the external magnetic fields applied. For example, it can change color from violet to red. It can be used for multi-colored magnetic boards that do not require a power source, next-generation display materials, and security ink. Furthermore, the ability to respond to the magnetic field enables it to be used in various applications such as drug delivery systems (DDS), as an MRI contrast agent, and in purifying filters

Monodispersed magnetically tunable ink (m-INK) is composed of photonic crystal nanoparticles that have a unique color originating from the physical structures of superparamagnetic nanoparticles in the solution. The color can be tuned by simply varying the interparticle distance using external magnetic fields. High-resolution, multi-colored patterns can also be created using m-INK without a color filter. This means you can make a color print without RGB pigments

Photonic color can be tuned by simple exposure to various external magnetic fields.
Monodispersed magnetically tunable ink (m-INK) is commercially available and the amounts used are insufficient to activate magnetic sensors built into up-to-date counterfeit detectors. This added layer of security is useful for currency, traveler?? checks, passports, and other financial and identity documents that require security measures

Characteristics SPM series
Formation Fe3O4-SiO2 or PS
Core Fe3O4
Shell Silica, PS
Crystal Form Sphere
Particle Size (nm) 80 - 170
Capsule Size (um) 30 - 500 um
Dispersion Medium Halocarbon Oil, Carbonate
Saturation Magnetization (emu/g) 80
Solid Content (wt%) 5-30
Specific Gravity (at 25) Various
pH Various
Color Range Red - Violet
Fr (in Gauss) 0 -500
Stabilizer (0.1 ~ 10%) AOT, ODTMS, OLOA