Towards Piezo-Nuclear Microgenerators: Beta Radiation Conversion Experiments and a Proposed Protocol

This technical note presents a research-grade protocol to test the hypothesis of direct piezoelectric conversion of beta radiation into electricity using static ceramic PZT and engineered PZT-X formulations. The approach is fully solid-state (no macroscopic mechanics), with single-lamella and multilayer “sandwich” geometries, guard-ring electrodes, and low-loss fixtures.

Irradiation is performed with a collimated Sr-90 source and with linac electron beams (0.5–2 MeV). Deposited power P_dep is operationally defined over the active piezo volume and estimated via Monte Carlo (e.g., Geant4, region tagging) and/or NIST PSTAR/ESTAR stopping-power data. Quantitative metrics include full I–V curves, open-circuit voltage (Voc), short-circuit current (Isc), maximum power point (P_max), and an electrical efficiency eta_elec = P_max / P_dep with a preregistered detectability target eta_elec >= 1e-4.

To ensure rigor and reproducibility, the protocol specifies blind controls (glass, sapphire, amorphous silicon), poled vs. unpoled PZT, and above-Tc checks; lock-in detection at off-mains frequencies with FFT/PSD analysis; a geometric-mechanical transfer parameter (kappa) calibrated on the real geometry; ABAB randomized sequences; and explicit Go/No-Go criteria. Practical sections cover dosimetry and graded-Z shielding, minimum instrumentation specifications (low-noise electrometer, charge preamplifier, synchronized DAQ, triax cabling in a Faraday cage), open-data deliverables, and a minimal power analysis to size experiments.

The study is designed to yield value regardless of outcome: a positive result would establish a new “radiopiezoelectric” conversion pathway; a null result would set meaningful bounds on the phenomenon.

Format: bilingual PDF — full English text followed by the complete Italian translation.

Note to Version 2:
This version is presented in English only and includes several clarifications and refinements in the description of the experimental protocol.

Note to Version 3
This version further develops the protocol by explicitly reframing the experimental objective around a hybrid betavoltaic–ferroelectric (BV+FE) architecture. In this scheme, wide-bandgap betavoltaic junctions (SiC, GaN, or diamond) provide the primary conversion of β deposition into electron–hole pairs, while an ultrathin ferroelectric layer (HfZrO₂ or engineered PZT-X) enhances charge separation, reduces recombination, and introduces a rectifying field effect.

The detection metrics are correspondingly updated: beyond the standard I–V characterization, the protocol specifies relative efficiency gain Δη_rel ≥ 20% of BV+FE versus BV-only devices as a preregistered success criterion, and the observation of a zero-bias current inversion with ferroelectric poling reversal as the unambiguous signature of the FE contribution.

Blind controls, lock-in detection, randomized ABAB sequences, and graded-Z shielding remain unchanged, while the documentation of Go/No-Go thresholds has been sharpened. The experimental plan now emphasizes the value of a null result as well: failure to observe the FE-induced signatures will conclusively bound the role of piezo/ferroelectric assist in betavoltaic architectures.

Format: English only.