X-ray Microscopy of Magnetic Nanostructures

Silicon Metasurfaces for DNA Synthesis
Abstract:
Ready access to long, accurate, and diverse synthetic DNA is essential for the rapid growth of synthetic biology — a field that genetically programs living cells with new functions. Modern microarray-based DNA synthesizers can generate diverse pools of oligonucleotide (single stranded DNA) sequences in parallel. However, each sequence is produced in limited quantity, and their yields decline with increasing oligo length due to cumulative synthesis errors. These limitations complicate downstream sequence segregation and gene assembly. Attempts to address these challenges by enlarging and spacing synthesis sites farther apart reduce the total number of sequences that can be generated simultaneously, thereby compromising synthesis diversity.
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In this talk, I will introduce B-MOS (Metasurface Oligonucleotide Synthesizer for Engineered Biology) — a novel platform that integrates silicon nanophotonics with solid-phase DNA synthesis to overcome these challenges.
B-MOS employs dielectric metasurfaces composed of arrays of high-index and low loss silicon nanoantennas (metasurfaces) patterned on glass as optically programmable synthesis sites. The unique optical signature of each metasurface — its spectral and polarization response — is lithographically encoded into the geometry and orientation of the silicon nanoantennas. Under global illumination, only the metasurface tuned to the wavelength and polarization of the laser absorbs the optical energy and transduces it into highly localized heat to site-selectively activate the synthesis reactions. Tuning the laser enables switching between the synthesis sites without moving parts or complex optical projection systems that lead to alignment errors.
As these nanostructures support sharp (high-Q) optical resonances, crosstalk between the synthesis sites is minimized. These sharp resonances allow the dense spectral packing of independently addressable synthesis within the tunable range of the laser, thereby maximizing synthesis diversity.
Using temperature as a programmable biochemical control knob, I will demonstrate site-selective enzymatic incorporation of fluorescent nucleotides onto surface-bound DNA using the enzyme terminal deoxynucleotidyl transferase. I will further discuss how integrating B-MOS with microfluidics can enable post-synthesis site-selective amplification and spatial segregation of oligo strands for reliable gene assembly.
Finally, I will outline how B-MOS can be extended to RNA and peptide synthesis as well as other enzyme-driven processes. By resonant nanophotonics with programmable biochemical control, B-MOS establishes a scalable physical foundation for high-precision biomolecular manufacturing and next-generation molecular technologies.
Speaker:
Dr. Punnag Padhy
Postdoctoral Scholar
Department of Materials Science and Engineering
Stanford University
AGENDA:
Thursday March 19, 2026
11:30 AM: Networking, Pizza & Drinks
Noon — 1 pm: Seminar
Please register on Eventbrite before 9:30 AM on Thursday March 19, 2026
$4 IEEE members $6 non IEEE members
(discounts for unemployed and students )
Bldg: ==> Use corner entrance: Kifer Road / San Lucar Court ==> Do not enter at main entrance on Kifer Road, EAG Labs, 810 Kifer Road, Sunnyvale, California, California, United States, 95051