Shahariar Ryehan
I Design and validate acoustic resonators and MEMS-compatible sensing systems from photoacoustic CO₂ gas sensors on chip or Mechanical device to built during a research internship at Hahn‑Schickard (Germany) to nonlinear wave models published in 5 peer-reviewed journals. Currently completing the Erasmus Mundus Joint Master WAVES, and looking ahead to a PhD in applied Electrical MEMS acoustic Sensors from scratch to advance.
research papers
A MEMS-Compatible Photoacoustic CO₂ Sensor
Seven months at Hahn‑Schickard (Villingen‑Schwenningen, Germany) designing, modeling, and experimentally validating a photoacoustic gas sensor from a baseline resonance cell to a tunable, MEMS‑ready Helmholtz resonator. My main target the whole way through: getting the resonator geometries right.
MEMS geometry, from mask to wafer
The resonator's cantilever microphone is fabricated on a two-mask silicon process: a silicon stack (500 nm AlN piezoelectric layer) and a gold stack (360 nm AlN, with a gold electrode pair) built up from thermal oxide, PECVD oxide, and patterned aluminium or gold on a bare silicon wafer. Dozens of geometry variants are patterned across a single wafer and diced apart, then characterized one-by-one with a laser Doppler vibrometer before being mounted into a resonator housing.
Trained across five institutions
A fully-funded two-year program spanning four countries in Europe, capped by a thesis placement at a fourth and bachelor's level at home country.
University of CoimbraPortugal
Universitat Politècnica de ValènciaSpain
Aix‑Marseille UniversitéFrance
Master's Thesis
Hajee Mohammad Danesh Science and Technology UniversityBangladeshFrom nonlinear wave equations to physical sensors
My research sits at the intersection of applied mathematics and experimental acoustics. I started out studying soliton solutions of nonlinear PDEs publishing on ocean waves modeled by the Kadomtsev–Petviashvili equation and on stochastic Bogoyavlenskii dynamics and have since moved into hardware: designing acoustic resonators, running thermoviscous FEM simulations in COMSOL, and building lumped‑element circuit models to make that hardware fast to iterate on.
I'm currently finishing the Erasmus Mundus Joint Master WAVES (Waves, Acoustics, Vibrations, Engineering and Sound) across the University of Coimbra, Universitat Politècnica de València, and Aix‑Marseille Université, and completed my thesis research at Hahn‑Schickard in Germany. I'm now looking for a PhD position where I can keep working on sensor physics, acoustic metamaterials, or nonlinear wave phenomena.
Education & research timeline
Research Intern / Master's Thesis
Designed and validated a MEMS-compatible photoacoustic CO₂ sensor: two resonator geometries, COMSOL FEM, and a lumped-element circuit model.
MSc, Acoustic & Vibration Engineering
Five lab placements: vibration & porous-materials work in Coimbra, electrical instrumentation in Valencia, granular-metamaterials internship and MEMS acoustic imaging in Marseille.
BSc & Research Assistant
Published research on soliton solutions of nonlinear PDEs; organized and taught mathematics/physics olympiad programs. Still working on photonic crystal fibers to detect perfect glucose in blood.
Papers & preprints
Unraveling Chaotic Dynamics in Variable-Order Fractional Systems
From Hertzian Contact to Pochhammer–Chree Dynamics: Solitons, Chaos & Bifurcation in Granular Metamaterials
Looking for a PhD position
I'm actively seeking doctoral opportunities in acoustics, MEMS sensing, vibration engineering, or applied mathematics for nonlinear wave phenomena. If any of this overlaps with your group's work, I'd love to talk.
Get in touch