Multidimensional Anisotropic Architectures on Polymeric Microparticles

Abstract

Next generation life science technologies will require the integration of building blocks with tunable physical and chemical architectures at the microscale. A central issue is to govern the multidimensional anisotropic space that defines these microparticle attributes. However, this control is limited to one or few dimensions due to profound fabrication tradeoffs, a problem that is exacerbated by miniaturization. Here, a vast number of anisotropic dimensions are integrated combining SU-8 photolithography with (bio)chemical modifications via soft-lithography. Microparticles in a 15-D anisotropic space are demonstrated, covering branching, faceting, fiducial, topography, size, aspect ratio, stiffness, (bio)molecular and quantum dot printing, top/bottom surface coverage, and quasi-0D, 1D, 2D, and 3D surface patterning. The strategy permits controlled miniaturization on physical dimensions below 1 µm and molecular patterns below 1 µm² . By combining building blocks, anisotropic microparticles detect pH changes, form the basis for a DNA-assay recognition platform, and obtain an extraordinary volumetric barcoding density up to 1093 codes µm^-3 in a 3 × 12 × 0.5 µm³ volume.

Keywords: anisotropy; barcoding; molecular multiplexing; polymer pen lithography; polymeric microparticles.