BACKGROUND:  Bottom-up synthesis can produce a very limited variety of particle shapes, such as spheres and rods, in a viscous liquid. The resulting particles can be highly uniform in size. However, there is no general method for mass-producing a wide variety of highly complex shapes that are specified by a customer using bottom-up self-assembly approaches. Although uniform microspheres have been used extensively in many protocols, these applications can be enhanced by using particles that have customized, user-specified shapes. Mass-producing particle shapes that conform with a desired design would revolutionize the variety of dispersions that are commercially available.

INNOVATION:  The invention described here uses directed, top-down processes facilitated by automated lithography, for rapid, massively parallel, high throughput production of particles of customizable shapes that exhibit high fidelity and uniformity. As a demonstration of the power of this invention, UCLA researchers have designed and fabricated "colloidal alphabet soup:" a dispersion of microscale polymer particles representing all twenty-six letters of the English alphabet in a viscous liquid. Submicron and nanoscale particles can be created by the same processes as well. Moreover, the internal composition, color, fluorescence, and 3-D structures of the particles can all be customized.

POTENTIAL APPLICATIONS:  Microscale LithoParticles, whose fluorescence and desired shape can be customized, can function as anti-counterfeit security inks to authenticate highly valuable documents or items. They could also serve as novel fluorescent probes for biological applications such as biological and molecular tagging and cell imaging.

ADVANTAGES

• High level of control over shapes, sizes, features, color and fluorescence
• Massively parallel high throughput production of particles
• Complex multi-layer 3D shapes and customizable internal compositions
• Ability to tailor functional surface groups to control stability and interactions

RELATED CASES: 

• 2007-138 "Mechanical Process for Creating Particles in a Fluid"
• 2008-015 "Process for modifying surfaces of particles made using spatially patterned radiation"
• 2008-016 "Processes for relief deposition templating"
• 2008-017 "Fabrication of custom particles using relief radiation templating"
• 2008-018 "Variations of processes for making particles by spatially patterned radiation"
• 2008-019 "Processes for modifying particles made using relief deposition templating"

Reference: UCLA Case No. 2007-008