Alan Bonilla Santos

Problem

Optical systems in widefield fluorescence microscopy suffer from wavefront aberrations that degrade resolution. Correcting these in real time at the micron scale requires precise actuation of a deformable mirror surface with hundreds of individually controllable actuators.

Approach

Operated Boston Micromachines MEMS deformable mirrors to reshape optical wavefronts. The Partitioned Aperture Wavefront (PAW) technique splits light through four off-axis lenses into quadrants; analyzing the intensity imbalance between quadrant pairs reveals local tilt: θ_x = NA·(I₁−I₂−I₃+I₄)/I_tot. Developed MATLAB scripts for automated actuation sequences, surface-response characterization (influence function mapping), and iterative calibration routines.

Tools Used

Results & Impact

Built applied expertise in adaptive optics systems used in cutting-edge biological microscopy and laser communications. Work feeds into the lab's ongoing conjugate adaptive optics research platform (Li et al., Optica 2015; Bifano et al., OE 2021).

Problem

Cardiovascular disease drives nearly a third of drug failures through unforeseen cardiac toxicity. Engineered tissue assays use fluorescent microbeads as fiducial markers to measure contractile force — but existing pipelines only processed one sample at a time and lacked sub-pixel precision.

Approach

Modeled each fluorescent bead as a 2D rotated Gaussian: F(X,Y) = A·exp(−[(X̄−x₀)²/2σ_x² + (Ȳ−y₀)²/2σ_y²]), where X̄,Ȳ are the rotated coordinates. Fitted this model to live bead images to extract sub-pixel center coordinates. Validated accuracy by imaging PDMS blocks with fixed bead pairs: computed inter-bead distance stayed within σ = 0.0819 px across 10 repositioned images (theoretical limit: 0.0188 px). Then parallelized the entire pipeline across all wells in a 96-well plate format.

Tools Used

Results & Impact

Achieved 96× throughput scale-up with ±0.15 µm precision, FDA-comparable fidelity, and selected for presentation at the 2026 ERN Conference (AAAS/NSF). System enables high-throughput cardiac drug-toxicity screening in regenerative medicine research.

Problem

Design a hybrid rocket nozzle for BURPG's hotfire test program that survives 80 psi chamber and 46 psi throat pressures, optimized for specific impulse and manufacturable via 3D printing.

Approach

Derived geometry from isentropic flow equations (Sutton, Rocket Propulsion Elements) — computing area ratio, throat/exit diameters, and 80% bell contour nozzle length. Custom material properties entered for ABS-like resin V2.0 (E = 2000 N/mm², yield = 25.2 N/mm²). FEA applied chamber pressure (80 psi, red) and throat pressure (46 psi, blue) simultaneously; bolt-hole regions fixed as constraints. Assembly connected via 6× ¼"-20 nuts and bolts to a 1" NPT chamber adapter.

Results & Impact

Von Mises max stress = 1.19×10⁷ N/m² (47% of yield), minimum FOS = 2.118 at bolt holes — design declared structurally safe. Results and safety documentation integrated into BURPG's hotfire test program.

Problem

Ensure stable rocket flight by optimizing fin geometry — maximizing stability margin (center-of-pressure behind center-of-mass) while minimizing aerodynamic drag to maximize apogee altitude.

Approach

Cross-validated aerodynamic models in both RASAero and OpenRocket to bound prediction uncertainty. Parametrically swept fin span, root chord, tip chord, and sweep angle to build a stability-vs-drag Pareto front. Validated simulated stability margins against SolidWorks mass-properties data. Coordinated results delivery across design and test teams.

Tools Used

Results & Impact

Delivered a validated fin configuration exceeding the minimum stability margin requirement with reduced drag, directly improving predicted apogee. Integrated into BURPG's active design program.