Ting-Yi ChenWEI-CHANG LI2025-05-222025-05-222025-01-19https://www.scopus.com/record/display.uri?eid=2-s2.0-105001665119&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/729624This work demonstrates for the first time micromechanical physical unclonable functions (PUFs) that leverage the unbalanced bimodal frequency combs of the internal-resonating MEMS resonator. In particular, this work utilizes the nonlinear CMOS-MEMS resonator that previously demonstrated the true random number generation (TRNG) based on the saddle-node on an invariant circle (SNIC) bifurcation point and operates it away from bifurcation, allowing stable frequency comb generation. Here, the frequency comb patterns serve as the process-variation-derived response upon a challenge determined by a particular driving frequency value, together forming a challenge-response pair. Digitizing the amplitude of the frequency comb with 16 bits for the highest 8 comb teeth generates a total of 16 × 8 = 128 PUF bits for a particular driving frequency with a single resonator. This device advances CMOS-MEMS technology into a new application area of MEMS-based PUF security.CMOS-MEMS platformfrequency combsinternal resonancenonlinear resonatorPhysical unclonable functionPUFconference paper10.1109/MEMS61431.2025.10918008