Piezoelectric materials — validated parameters
Source agent: h02 parameter provenance audit (Sonnet 4.6), 2026-04-23. Consumer: piezo_voltage_budget.py, piezo_phase2_frequency_bundle.py.
Parameter table
| Parameter | Value | Source | Conditions | Status | Notes |
|---|---|---|---|---|---|
| PVDF-TrFE (70/30) d31 | −8 to −12 pC/N | Manufacturer specs (Arkema Piezotech, APC Int’l) | β-phase, poled film | ⚠ manufacturer | Conservative range; well-poled film may reach −25 pC/N |
| PVDF-TrFE (70/30) d33 | >20 pC/N | Arkema Piezotech; Frontiers Energy 2021 in-situ poling | β-phase | ⚠ manufacturer | d31 and d33 are related but different modes |
| PVDF-TrFE (70/30) eps_r | 8.0–9.0 | Arkema Piezotech datasheet; piezopvdf.com | 1 kHz, 25°C | ⚠ manufacturer | Script uses 10.0 — slightly high |
| PVDF-TrFE (70/30) E_mod | >3 GPa | Arkema Piezotech datasheet | bulk film | ⚠ manufacturer | Research range 1.5–4 GPa for thin films |
| P(VDF-TrFE-CFE) terpolymer d33 | ~40 pm/V (≈40 pC/N) | Arkema Piezotech; relaxor ferroelectric literature | low-field, unpoled | ⚠ manufacturer | d31 somewhat lower; exact value composition-dependent |
| P(VDF-TrFE-CFE) eps_r | >50 | Arkema Piezotech; piezopvdf.com CFE07 product | 1 kHz, 25°C | ⚠ manufacturer | Consistent with script value of 50 |
| P(VDF-TrFE-CFE) E_mod | ~1.2 GPa | estimate (softer than copolymer) | — | ❌ | No primary paper found; plausible direction |
| PLLA d14 (shear mode) | ~10 pC/N | — | — | ❌ | PLLA is shear (d14), not transverse (d31). Scripts treat d14 as equivalent to d31 — this is a model approximation requiring flagging. |
| BaTiO3 d31 | −78 pC/N | textbook / standard | bulk ceramic | ✅ | Reference only; Ba²⁺ toxicity precludes cochlear use |
| No-poling PVDF-TrFE (PEDOT:PSS templated) | enhanced β-phase, d33 not yet quantified | 2026-04-21-wu-pvdf-trfe-pedotpss-piezoelectric (Wu et al. ACS AEM 2026, PMID 42004736) | PEDOT:PSS + paper substrate | ✅ paper note exists | Key fabrication advance: eliminates high-voltage poling step |
Phase 1 vs Phase 2 d31 inconsistency
CRITICAL FLAG: piezo_voltage_budget.py uses d31 = −12 pC/N for PVDF-TrFE; piezo_phase2_frequency_bundle.py uses d31 = −25 pC/N for the identical material. This 2× discrepancy propagates into all voltage outputs. The Phase 2 value (−25 pC/N) is achievable for well-poled film; the Phase 1 value (−12 pC/N) is conservative β-phase. Neither is cited. Scripts must be reconciled to a single canonical value with a primary literature source.
Recommended canonical value: d31 = −12 pC/N (conservative, β-phase, consistent with manufacturer range 8–12 pC/N) until a primary paper is cited for the higher value.
OHC membrane constants (from same scripts, electroacoustic interface)
| Parameter | Value | Source | Status | Notes |
|---|---|---|---|---|
| OHC specific membrane capacitance | 0.9 µF/cm² (9e-3 F/m²) | Gentet et al. 2000, Biophys J 79:314–320 | ⚠ NEEDS PDF | Scripts cite “Ashmore 1987” but 0.9 µF/cm² is Gentet 2000. Ashmore 1987 (J Physiol 388:323) established electromotility; specific capacitance was quantified later. |
| OHC specific membrane resistance | ~kΩ·cm² (1e-3 Ω·m²) | generic excitable membrane | ❌ NEEDS LITERATURE | No primary OHC-specific citation in scripts. |
| Prestin operating voltage threshold | 10 mV (model gate) | Santos-Sacchi 1991, J Neurosci 11:3096 (PMID 1941076) | ⚠ NEEDS PDF | Paper exists and is the correct reference for NLC voltage sensitivity. “10 mV threshold” is a model simplification — prestin NLC operates over −150 to +50 mV; 10 mV is the signal modulation amplitude assumed sufficient for amplification. |
| Prestin V_saturation | 70 mV | no citation | ❌ NEEDS LITERATURE | Unsourced. |
Papers to retrieve for this topic
| Paper | What it provides |
|---|---|
| Ashmore JF (1987) J Physiol 388:323–347 | OHC electromotility origin; correct citation for C_spec claim |
| Gentet LJ et al. (2000) Biophys J 79:314–320 | Specific membrane capacitance 0.9 µF/cm² |
| Santos-Sacchi J (1991) J Neurosci 11:3096 (PMID 1941076) | Prestin NLC voltage dependence |
| Arkema Piezotech PVDF-TrFE datasheet | d31, eps_r, E_mod — manufacturer values for modelling |
| Wu et al. (2026) ACS AEM PMID 42004736 | No-poling β-phase PVDF-TrFE via PEDOT:PSS — paper note already exists |
Connections
[part-of]_hub (literature-params)[applies]STRC Piezoelectric TM Bioelectronic Amplifier[see-also]2026-04-21-wu-pvdf-trfe-pedotpss-piezoelectric[see-also]2026-04-21-yin-piezoelectric-pvdf-bt-bone[see-also]tectorial-membrane (companion topic file)