Case Study: Siemens Healthineers achieves optimized piezoelectric MEMS energy harvester for battery-free in-tire TPMS with COMSOL Multiphysics

Modeling Optimizes a Piezoelectric Energy Harvester used in Car Tires

Siemens Healthineers set out to develop a battery‑free piezoelectric MEMS energy harvester to power an in‑tire TPMS, requiring an extremely small, lightweight assembly able to survive up to 2,500 g and deliver an operational life of at least eight years. The main technical challenge was minimizing air damping of a triangular cantilever (area ≤100 mm²) by optimizing its shape and layer thicknesses; to avoid costly, time‑consuming fabrication cycles Siemens Healthineers used Comsol’s COMSOL Multiphysics simulation software.

Using Comsol, the team performed 2‑D and 3‑D fluid–structure interaction simulations to evaluate cantilever deflection, stress, and damping across carrier thicknesses (e.g., 50, 95, 250 µm) and gas pressures (1–3 bar). The simulations, calibrated with experimental data to include internal material losses, showed increased carrier thickness improved damping and accurately predicted device behavior. Comsol enabled virtual testing of up to ~2,000 prototype variants in the time of one physical run, substantially reducing the need for expensive clean‑room runs (>€100,000 and ~6 months per run) and accelerating cost‑effective optimization of the MEMS harvester.

Siemens Healthineers

Ingo Kuehne

Siemens