STRC Research

STRC h02 Parameter Provenance Audit 2026-04-25

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STRC h02 Piezo — Parameter Provenance Audit 2026-04-25 (Blocker Closure)

Continuation of STRC h02 Parameter Provenance Audit 2026-04-23. Closes 3 specific blockers flagged by the 04-25 cross-hypothesis sweep: (1) TM displacement phantom citations; (2) TM Young’s modulus 24–210 kPa misattribution; (3) Arkema PVDF-TrFE datasheet alternatives.

Context

The 04-23 audit caught 4 citation errors and demoted h02 from S → B tier. Three blockers remained open in tectorial-membrane.md and piezoelectric-materials.md. This phase closes those three blockers.

Blocker 1 — TM displacement 5–30 nm at 60 dB SPL

Phantom citations confirmed destroyed:

  • “Gueta 2006” — does not exist. Real paper is Gueta 2008 Biophys J 94:4570 (PMID 18310237), which reports TM stiffness anisotropy, not absolute nm displacement values. Previously confirmed.
  • “Ren 2011” — does not exist in PubMed. Ren 2002 PNAS 99:17101 (PMID 12461165) measures BM wave phase in gerbil basal turn, not TM nm displacement. Previously confirmed.

Search for real primary source:

  • Cooper & Rhode 1996 J Neurophysiol: searched; not retrievable via PubMed open access; content of the 1996 paper cannot be confirmed for absolute TM nm values.
  • Gummer, Hemmert & Zenner 1996 PNAS 93:8727 (PMID 8710939): measures TM motion in guinea pig in two orthogonal directions via laser interferometry; full-text nm values not confirmed (PMC not available; Anna’s Archive does not index PNAS journals).
  • Lee HY et al. 2015 PNAS 112:3128 (PMID 25737536, Oghalai lab, volumetric OCT): reports mouse TM peak magnitude ~20 nm at 20 dB SPL and ~90 nm at 80 dB SPL at CF ~7.5–9 kHz. This is the closest confirmed primary measurement. Interpolation to 60 dB → ~35–40 nm.

Verdict: The 5–30 nm at 60 dB SPL is an IN-HOUSE MODEL ASSUMPTION. No single primary paper provides the frequency-dependent table (200 Hz → 8000 Hz) used in TM_DISP_60dB in piezo_phase2_frequency_bundle.py. The values are order-of-magnitude consistent with Lee 2015 but the specific table is a model parameterization.

Actions taken:

  • piezo_phase2_frequency_bundle.py: TM_DISP_60dB comment block replaced with explicit WARNING documenting phantom citations and Lee 2015 as closest anchor.
  • piezo_voltage_budget.py: phantom journal citation “Ren 2002 Nat Neurosci 5:169” corrected to “Ren 2002 PNAS 99:17101” + WARNING block added.
  • literature/tectorial-membrane.md: TM displacement rows updated from ❌ CITATION PHANTOM → ⚠ MODEL ASSUMPTION with Lee 2015 and Gummer 1996 context.

Blocker 2 — TM Young’s modulus 24–210 kPa

“Masaki 2009 PLoS One 4:e4877” phantom: Previously confirmed in 04-23 audit. That DOI = Gavara & Chadwick 2009, fiber modulus ~1 kPa.

Search for real source of 24 kPa:

  • Teudt IU & Richter CP (2014) JARO 15:675–694 (PMID 24865766, DOI 10.1007/s10162-014-0463-y): Found and confirmed. Reports TM Young’s modulus in CBA/CaJ mouse by direct probe indentation:
    • Basal: 24.3 ± 25.2 kPa
    • Middle: 5.1 ± 4.5 kPa
    • Apical: 1.9 ± 1.6 kPa This is the real primary source for the “24 kPa” value. Critical correction: 24 kPa is the BASAL modulus, not apical. Scripts that implied 24 kPa is apical are wrong in that interpretation.
  • Shoelson B et al. (2004) Biophys J 87:2768 (PMID 15454468): AFM shear modulus map of guinea pig TM. Aggregate G’ = 2.0–6.5 kPa (depending on probe/model). Does NOT report Young’s modulus or values near 24–210 kPa. Context only.

Search for real source of 210 kPa:

  • NOT FOUND. Teudt 2014 max = 24.3 kPa (basal). Shoelson 2004 max = 6.5 kPa. Gavara 2009 fiber ~1 kPa. Gueta 2008 vertical compressive modulus = 300 kPa (different loading axis; closest to 210 range but not the same). The “210 kPa” figure in h02 scripts has no confirmed primary source.

Actions taken:

  • New paper note: papers/2026-04-25-teudt-2014-tm-bm-stiffness-cba-mouse.md — confirmed primary source for 24 kPa (basal TM).
  • New paper note: papers/2026-04-25-shoelson-2004-tm-elasticity-inhomogeneity-biophysj.md — shear modulus 2–6.5 kPa; context only.
  • literature/tectorial-membrane.md: TM Young’s modulus rows updated. 24 kPa row changed from ❌ CITATION ERROR → ✅ SOURCED with Teudt 2014. 210 kPa row added as ❌ NO PRIMARY SOURCE. Shoelson 2004 added as context row.

Blocker 3 — Arkema PVDF-TrFE datasheet alternatives

piezopvdf.com confirmed 403 (inaccessible, previously noted).

piezotech.arkema.com: no numerical specs published publicly. Redirected domain; homepage has qualitative descriptions only.

Fukada & Furukawa 1981 Ultrasonics 19:31: Retrieved abstract. This paper covers PVDF (not PVDF-TrFE copolymer) and is a 1981 review. Cannot serve as primary source for 70/30 copolymer d31.

Frontiers Energy 2021 paper retrieved: Hu X et al. (2021) Front Energy Res 9:621540 (DOI 10.3389/fenrg.2021.621540). Reports d33 = 25–28 pC/N for PVDF-TrFE 80/20 (FC20, Piezotech SAS) via in-situ poling. Peer-reviewed. Key caveats: (1) composition is 80/20 not 70/30; (2) only d33 measured, not d31; (3) d31 can be inferred as ~−10 to −14 pC/N from known d31/d33 ratio ~0.4–0.5 for PVDF-TrFE, consistent with the −12 pC/N used in scripts.

Verdict for PVDF-TrFE d31: The Arkema datasheet (d31 = −8 to −12 pC/N) remains the primary source but is inaccessible. Hu 2021 provides peer-reviewed d33 corroboration for the order of magnitude. The d31 = −12 pC/N used in scripts is consistent with all available evidence but lacks a single open-access peer-reviewed primary citation giving this exact value for 70/30 composition. Status upgraded from ⚠ (no peer-reviewed source) to ⚠ partial (peer-reviewed d33 for related composition; d31 inferred).

Actions taken:

  • New paper note: papers/2026-04-25-hu-2021-pvdftrfe-insitu-poling-frontiers-energy.md
  • literature/piezoelectric-materials.md: d33 row updated from ⚠ manufacturer to ⚠ partial with Hu 2021 paper note. Arkema datasheet row updated to reflect failure to retrieve and Fukada 1981 inapplicability. Connections updated.

TM displacement + Young’s modulus follow-up (this section)

IssuePrior statusThis agent’s actionPost-action status
TM displacement 5–30 nm❌ CITATION PHANTOMSearched Cooper 1996, Gummer 1996, Lee 2015; demoted to model assumption; WARNING added to both scripts⚠ MODEL ASSUMPTION (explicit WARNING in scripts)
TM Young’s modulus 24 kPa❌ CITATION ERROR (phantom “Masaki 2009”)Found Teudt & Richter 2014 JARO PMID 24865766; paper note written; tectorial-membrane.md updated✅ SOURCED (basal CBA/CaJ mouse)
TM Young’s modulus 210 kPa❌ CITATION ERRORSearched; not found in any retrieved paper. 300 kPa (Gueta 2008 vertical modulus) is closest analog but not the same❌ NO PRIMARY SOURCE — must be removed or flagged in scripts
Arkema datasheet d31⚠ manufacturer inaccessibleRetrieved Hu 2021 (d33 for 80/20); Fukada 1981 is PVDF not copolymer⚠ partial (peer-reviewed d33 80/20; d31 inferred)
Frontiers Energy 2021⚠ not retrievedRetrieved: Hu et al. 2021 Front Energy Res 9:621540✅ retrieved, paper note written

Script docstring updates applied

FileChange
models/piezo_phase2_frequency_bundle.pyTM_DISP_60dB comment block: phantom citations removed; WARNING block added citing Lee 2015 PNAS as closest anchor
models/piezo_voltage_budget.py”Ren 2002 Nat Neurosci 5:169” corrected to “Ren 2002 PNAS 99:17101”; full WARNING block added to TM displacement model section with explicit phantom documentation

Ranking delta

h02 tier remains B. No model output changes this turn — only citation corrections and model-assumption documentation. The 210 kPa figure remains in scripts (not yet removed; flagged for user decision). Mechanical mismatch concern (PVDF-TrFE 3 GPa vs TM 24 kPa basal, 1.9 kPa apical) is now quantified with a real primary source.

lit_audit status: partial — TM displacement confirmed as model assumption (not fixable without new experiment); TM Young’s modulus 24 kPa confirmed sourced; 210 kPa unresourced; d31 partially sourced.

No tier change. No mech/deliv/misha_fit change.

Connections

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