Columbia University

Technology Ventures

Modification of surfaces with nanoparticles using a photo-chemical approach

Technology #m10-009

Nanoparticles are utilized in electronic as well as biomedical applications for surface modification. However, current techniques lack the spatial resolution and ability to effectively pattern graft nanoparticles to a substrate. This technology uses a chemical compound with varying functional end groups called phthalimides as a photo-initiator for grafting nanoparticles to surfaces. For grafting to soft substrates, phthalimide-functionalized nanoparticles are spin-coated onto a polymeric substrate. For grafting from a hard substrate, phthalimide covers the surface of the substrate in a self-assembled monolayer (SAM), and nanoparticles are spin-coated onto the SAM. In both cases, following spin-coating, UV light exposure crosslinks the nanoparticles to the substrate surface. Photo-masks placed between the nanoparticle-coated surface and UV light source can further vary light intensity reaching the photo-initiators, thus allowing for spatial patterning over the nanoparticle crosslinking area.

Photo-grafting allows for increased control and spatial resolution of nanoparticle substrate coating

The photo-initiators described in this technology can crosslink nanoparticles to a surface depending on light intensity exposure. For this reason, photo-masks, which can be printed with ink to allow more or less light through, permit targeting of specific areas for cross-linked nanoparticles. Spatial resolution allows for improved accuracy and reproducibility in manufacturing surface-modified electronics. Additionally, substrates with grafted nanoparticles can potentially have higher durability and longevity.

Photo-grafting of particles to and from soft and hard substrates, respectively, has been demonstrated using surface analysis of contact angle goniometry, x-ray photoelectron spectroscopy, fluorescence spectroscopy, and scanning electron microscopy.

Lead Inventor:

Jeffrey T. Koberstein, Ph.D.


  • Electronic applications including high density digital data storage, touch screens, and photovoltaic applications.
  • Biomedical applications including biosensors and drug delivery nanoparticle substrate coatings.


  • Controllable spatial resolution of nanoparticle patterning using lithography and photo-masks.
  • Controllable thickness of grafted surface.
  • Increased durability against scratch, tear, and chemical resistance.
  • Can tailor choice of photo-active linkers and nanoparticles for specific use.

Patent information:

Patent Pending (US 20110059264)

Licensing Status:

Available for licensing and sponsored research support

Tech Ventures Reference: IR M10-009

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