STRC Research

piezoelectric-materials

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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

ParameterValueSourceConditionsStatusNotes
PVDF-TrFE (70/30) d31−8 to −12 pC/NManufacturer specs (Arkema Piezotech, APC Int’l)β-phase, poled film⚠ manufacturerConservative range; well-poled film may reach −25 pC/N. Arkema PDF not retrieved this turn — manufacturer datasheet remains primary source, no peer-reviewed paper note yet.
PVDF-TrFE (70/30) d33~25–28 pC/N (closely related 80/20 composition)2026-04-25-hu-2021-pvdftrfe-insitu-poling-frontiers-energy (Hu et al. 2021, Front Energy Res 9:621540, DOI 10.3389/fenrg.2021.621540)β-phase, in-situ poling, 80/20 mol% — not 70/30⚠ partial (different composition)Peer-reviewed d33 = 25–28 pC/N for PVDF-TrFE 80/20 (FC20, Piezotech). Composition differs from h02’s 70/30. d31 not measured. Consistent with manufacturer range for d33; d31 ≈ −10 to −14 pC/N inferred from d31/d33 ratio ~0.4–0.5. Full manufacturer datasheet (Arkema) remains inaccessible (403 on piezopvdf.com).
PVDF-TrFE (70/30) eps_r8.0–9.0Arkema Piezotech datasheet; piezopvdf.com1 kHz, 25°C⚠ manufacturerScript uses 10.0 — slightly high
PVDF-TrFE (70/30) E_mod>3 GPaArkema Piezotech datasheetbulk film⚠ manufacturerResearch range 1.5–4 GPa for thin films
P(VDF-TrFE-CFE) terpolymer d33~40 pm/V (≈40 pC/N)Arkema Piezotech; relaxor ferroelectric literaturelow-field, unpoled⚠ manufacturerd31 somewhat lower; exact value composition-dependent
P(VDF-TrFE-CFE) eps_r>50Arkema Piezotech; piezopvdf.com CFE07 product1 kHz, 25°C⚠ manufacturerConsistent with script value of 50
P(VDF-TrFE-CFE) E_mod~1.2 GPaestimate (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/Ntextbook / standardbulk ceramic✅Reference only; Ba²⁺ toxicity precludes cochlear use
No-poling PVDF-TrFE (PEDOT:PSS templated)enhanced β-phase, d33 not yet quantified2026-04-21-wu-pvdf-trfe-pedotpss-piezoelectric (Wu et al. ACS AEM 2026, PMID 42004736)PEDOT:PSS + paper substrate✅ paper note existsKey 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)

ParameterValueSourceStatusNotes
OHC specific membrane capacitance0.9 µF/cm² (9e-3 F/m²)2026-04-25-gentet-2000-specific-membrane-capacitance-neurons (Gentet et al. 2000, Biophys J 79:314–320, PMID 10866957)✅ paper note existsCorrection: Scripts cite “Ashmore 1987” for this value — wrong attribution. Gentet 2000 is the source. Second caveat: Gentet measured general neurons (cortical, spinal, hippocampal + HEK-293), not OHCs. Extrapolation to OHC is defensible (“biological constant” claim) but should be flagged in scripts. Ashmore 1987 established electromotility (19.8 nm/mV), not Cm.
OHC specific membrane resistance~kΩ·cm² (1e-3 Ω·m²)generic excitable membrane❌ NEEDS LITERATURENo primary OHC-specific citation in scripts. No paper retrieved this turn — remains open gap.
Prestin operating voltage threshold10 mV (model gate)2026-04-25-santos-sacchi-1991-prestin-nlc-voltage (Santos-Sacchi 1991, J Neurosci 11:3096, PMID 1941076)✅ paper note existsPaper confirmed. NLC peaks at −40 mV (AC method); “10 mV threshold” is a model simplification not in Santos-Sacchi — it is the signal modulation amplitude, not a NLC threshold. Full C-V range is approximately −150 to +50 mV.
Prestin V_saturation70 mVno citation❌ NEEDS LITERATUREUnsourced. NOT in Santos-Sacchi 1991. The Boltzmann C-V function has no discrete saturation voltage at 70 mV. Value requires a primary source or must be removed from scripts.

Papers to retrieve for this topic

PaperWhat it providesStatus
Ashmore JF (1987) J Physiol 388:323–347, PMID 3656195OHC electromotility origin; confirms NOT the source of Cm✅ paper note: 2026-04-25-ashmore-1987-ohc-electromotility-jphysiol
Gentet LJ et al. (2000) Biophys J 79:314–320, PMID 10866957Specific membrane capacitance 0.9 µF/cm² (general neurons, not OHC-specific)✅ paper note: 2026-04-25-gentet-2000-specific-membrane-capacitance-neurons
Santos-Sacchi J (1991) J Neurosci 11:3096, PMID 1941076Prestin NLC voltage dependence: V_half −40 mV (AC), max NLC 16–17 pF✅ paper note: 2026-04-25-santos-sacchi-1991-prestin-nlc-voltage
Arkema Piezotech PVDF-TrFE datasheetd31, eps_r, E_mod — manufacturer values for modelling❌ inaccessible — piezopvdf.com returns 403; piezotech.arkema.com has no numerical specs publicly. Fukada & Furukawa 1981 (Ultrasonics 19:31) covers PVDF not PVDF-TrFE copolymer; insufficient for 70/30 copolymer d31. Values remain manufacturer-sourced with no open peer-reviewed alternative for d31 specifically.
Frontiers Energy 2021 in-situ poling paperPVDF-TrFE d33 corroboration✅ RETRIEVED 2026-04-25: Hu et al. 2021 DOI 10.3389/fenrg.2021.621540. d33 = 25–28 pC/N for 80/20 (FC20, Piezotech). NOTE: 80/20 not 70/30; d31 not measured. 2026-04-25-hu-2021-pvdftrfe-insitu-poling-frontiers-energy
Wu et al. (2026) ACS AEM PMID 42004736No-poling β-phase PVDF-TrFE via PEDOT:PSS✅ paper note already exists: 2026-04-21-wu-pvdf-trfe-pedotpss-piezoelectric

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