A Piezoelectric MEMS True Random Number Generator Driven by Amplitude-Modulated Internal Resonance

This work demonstrates a true random number generator (TRNG) in a 1:2 internal resonant (IR) ScAIN piezoelectric resonator driven by an amplitude-modulated (AM) signal. While IR alone establishes a dynamic twowell potential with two localized energy states, the addition of AM pumping facilitates the system to transition between these states and the resonator's trivial low-energy state. The synergy between IR and AM engineers a dynamic multi-well potential landscape, where the complex evolution between energy potentials results in chaotic vibrations ideal for generating unpredictable bitstreams. By introducing a pseudo XOR operation to the chaotic vibration and selecting the 3 least significant bits (LSBs), this approach achieves a 450-kbps throughput at a 150 kHz sampling rate and validates a high-quality entropy. In particular, a 1.125-Mbit bitstream generated in 2.5 seconds successfully passes NIST 800-22 and NIST 800-90B IID (independent and identically distributed) tests and shows a non-IID min-entropy of 0.878368, confirming the AMdriven IR resonator as a robust entropy source for cryptographic applications.