spore: profile
id: pvdf-piezo-film
spore_version: 0.2
family: fluoropolymers
name: Piezoelectric PVDF film
abbreviation: PVDF film
role: poled, stretched fluoropolymer film for piezoelectric sensors, impact switches and transducers
category: polymers
type: fluoropolymers
summary: Piezoelectric PVDF film is a thin, flexible sheet of poled polyvinylidene fluoride (PVDF). It produces an electric charge when it is stressed and changes shape when a field is applied. The Measurement Specialties manual lists a mass density of 1.78 g/cm3, a d31 strain constant of 23 (10^-12 m/V) and a limit of 100 °C for use or storage. The manual also reports that the sensor has been used to detect high-speed particle impacts in space.
best_for: Light, flexible strain, pressure and impact sensors used below 100 °C
weakest_at: 'Heat and atomic oxygen: the manual limits use to 100 °C, and PVDF erodes in low Earth orbit (MISSE 2 flight sample)'
identity:
  formula: (C2H2F2)n, with repeat unit C2H2F2 (vinylidene fluoride monomer)
  source: nasa-tm-2008-215490
  where: Table IV (PVDF Kynar row, formula C2H2F2); Table V (atom counts)
tags:
  environments:
    - low-earth-orbit
  stresses:
    - atomic-oxygen
    - uv
    - total-radiation-dose
  applications:
    - electronics-and-chips
    - optics-and-cameras
    - structures
properties:
  - benchmark: density
    label: Mass density, piezo film (PVDF)
    value: 1.78
    unit: g/cm3
    scope: material
    conditions:
      unit_in_source: 10^3 kg/m3 (printed as 1.78 with the unit 10^3 kg/m3)
      temperature: not printed
    method: Typical value printed in the manual's Table 1 (Mass Density, PVDF column). The printed unit is 10^3 kg/m3, which equals g/cm3 numerically.
    status: ground
    source: piezo-manual
    where: Table 1, Mass Density row (PVDF column); Table 2, Density row
  - benchmark: dielectric_constant
    label: Relative permittivity, piezo film (PVDF)
    value: 12
    value_high: 13
    bound: range
    unit: '-'
    scope: material
    conditions:
      frequency: not printed
    method: Typical values printed in Table 1 (Relative Permittivity, PVDF column). Table 2 gives 12 for PVDF film.
    status: ground
    source: piezo-manual
    where: Table 1, Relative Permittivity row (PVDF column); Table 2, Relative Permittivity row
  - benchmark: dissipation_factor
    label: Loss tangent, piezo film (PVDF)
    value: 0.02
    unit: '-'
    scope: material
    conditions:
      frequency: 1 kHz
    method: Typical value printed in Table 1 as tan delta e, Loss Tangent 0.02 at 1 kHz (PVDF column).
    status: ground
    source: piezo-manual
    where: Table 1, Loss Tangent row (PVDF column)
  - benchmark: capacitance_per_area
    label: Capacitance per unit area, 28 um PVDF film
    value: 380
    unit: pF/cm2
    scope: material
    conditions:
      thickness: 28 µm
      frequency: 1 kHz
    method: Typical value printed in Table 1 (Capacitance row, PVDF column) for a 28 µm film.
    status: ground
    source: piezo-manual
    where: Table 1, Capacitance row (PVDF column)
  - benchmark: piezo_d31
    label: Piezo strain constant d31, piezo film (PVDF), 1 direction
    value: 23
    unit: 10^-12 m/V
    scope: material
    conditions:
      direction: 1 (length or stretch) direction
      printed_in_table_2: 23 in (10^-12) C/N
    method: Printed as 23 x 10-12 m/V in the operating-properties section for a typical piezo film element, item 1. Table 2 prints the same 23 for PVDF film with unit (10^-12) C/N.
    status: ground
    source: piezo-manual
    where: Operating Properties for a Typical Piezo Film Element, item 1 (1 direction); Table 2, d31 Constant row
  - benchmark: piezo_d33
    label: Piezo strain constant d33, piezo film (PVDF), 3 direction
    value: -33
    unit: 10^-12 m/V
    scope: material
    conditions:
      direction: 3 (thickness) direction
    method: Printed as -33 x 10-12 m/V in the operating-properties section for a typical piezo film element, item 1. Table 1 prints d33 as -33 for PVDF.
    status: ground
    source: piezo-manual
    where: Operating Properties for a Typical Piezo Film Element, item 1 (3 direction); Table 1, d33 row
  - benchmark: piezo_g31
    label: Piezo stress constant g31, piezo film (PVDF)
    value: 216
    unit: 10^-3 V·m/N
    scope: material
    conditions:
      stress_direction: 1 (stretch) direction
    method: Printed as 216 in Table 2 (g31 Constant, unit (10^-3) Vm/N, PVDF Film). Table 1 also gives 216 for PVDF.
    status: ground
    source: piezo-manual
    where: Table 2, g31 Constant row; Table 1, g31 row (PVDF column)
  - benchmark: electromechanical_coupling_k31
    label: Electromechanical coupling factor k31, piezo film (PVDF)
    value: 12
    unit: '%'
    scope: material
    conditions:
      frequency: 1 kHz
    method: Printed as k31 Constant 12 % at 1 KHz in Table 2 (PVDF Film). Table 1 gives 12% for PVDF.
    status: ground
    source: piezo-manual
    where: Table 2, k31 Constant row; Table 1, k31 row
  - benchmark: coupling_factor_kt
    label: Thickness-mode coupling factor kt, piezo film (PVDF)
    value: 14
    unit: '%'
    scope: material
    conditions:
      basis: coupling factor kt, PVDF column of Table 1
    method: Printed as 14% for PVDF in Table 1 (kt Coupling Factor row).
    status: ground
    source: piezo-manual
    where: Table 1, kt Coupling Factor row (PVDF column)
  - benchmark: elastic_modulus
    label: Young's modulus, piezo film (PVDF)
    value: 2
    value_high: 4
    bound: range
    unit: GPa
    scope: material
    conditions:
      unit_in_source: 10^9 N/m2 (printed as 109 N/m2)
      direction: not printed
    method: Printed as 2-4 for PVDF in Table 1, with the unit 10^9 N/m2. Converted to GPa, which is the same number.
    status: ground
    source: piezo-manual
    where: Table 1, Young's Modulus row (PVDF column)
  - benchmark: yield_strength
    label: Yield strength, piezo film (PVDF), stretch axis
    value: 45
    value_high: 55
    bound: range
    unit: MPa
    scope: material
    conditions:
      axis: stretch axis
      unit_in_source: 10^6 N/m2
    method: Printed as 45-55 for PVDF in Table 1, with the unit 10^6 N/m2 (stretch axis). Converted to MPa, which is the same number.
    status: ground
    source: piezo-manual
    where: Table 1, Yield Strength row (PVDF column)
  - benchmark: stress_without_failure
    label: Stress applied to a 52 µm film without failure
    value: 350
    unit: MPa
    scope: material
    conditions:
      thickness: 52 µm
      direction: stretch (n = 1) direction
      reported_as: approximately 350 MPa
    method: 'Manual text on dynamic range: a recent study subjected a 52 µm thick film to approximately 350 MPa in the stretch direction without failure.'
    status: ground
    source: piezo-manual
    where: Dynamic Range section (text)
  - benchmark: min_service_temp
    label: Lower end of the temperature range, piezo film (PVDF)
    value: -40
    unit: °C
    scope: material
    conditions:
      basis: Temperature Range row, PVDF column
    method: Table 1 prints a temperature range of -40 to 80...100 °C for PVDF.
    status: ground
    source: piezo-manual
    where: Table 1, Temperature Range row (PVDF column)
  - benchmark: max_service_temp
    label: Upper service limit, piezo film (PVDF)
    value: 100
    bound: upper
    unit: °C
    scope: material
    conditions:
      basis: 'manual text: not recommended for use or storage above 100 °C'
    method: Text in the Piezoelectric Film Properties section says PVDF is not recommended for use or storage above 100 °C (the degree sign prints garbled). Table 1 prints 80...100 for the upper range.
    status: ground
    source: piezo-manual
    where: Piezoelectric Film Properties section (text); Table 1, Temperature Range row
  - benchmark: max_operating_field
    label: Maximum operating voltage per thickness, piezo film (PVDF), DC
    value: 30
    unit: V/µm
    scope: material
    conditions:
      field: DC, 25 °C
      printed_as: 750 (30) V/mil (V/µm)
    method: Table 1 prints Maximum Operating Voltage 750 (30) V/mil (V/µm), DC, at 25 °C for PVDF. The 30 is the value in V/µm.
    status: ground
    source: piezo-manual
    where: Table 1, Maximum Operating Voltage row (PVDF column)
  - benchmark: dielectric_strength
    label: Breakdown voltage per thickness, piezo film (PVDF), DC
    value: 80
    unit: V/µm
    scope: material
    conditions:
      field: DC, 25 °C
      printed_as: 2000 (80) V/mil (V/µm)
    method: Table 1 prints Breakdown Voltage 2000 (80) V/mil (V/µm), DC, at 25 °C for PVDF. The 80 is the value in V/µm.
    status: ground
    source: piezo-manual
    where: Table 1, Breakdown Voltage row (PVDF column)
  - benchmark: moisture_absorption
    label: Water absorption, piezo film (PVDF)
    value: 0.02
    bound: upper
    unit: '%'
    scope: material
    conditions:
      basis: water absorption as H2O, PVDF column
    method: Printed as <0.02 % H2O for PVDF in Table 1. The text repeats it as <0.02% moisture absorption.
    status: ground
    source: piezo-manual
    where: Table 1, Water Absorption row (PVDF column); Piezoelectric Film Properties section (text)
  - benchmark: pyroelectric_coefficient
    label: Pyroelectric coefficient, piezo film (PVDF)
    value: 30
    unit: 10^-6 C/(m2·K)
    scope: material
    conditions:
      basis: PVDF column of Table 1
      printed_unit: 10-6 C/m2 bK (the last symbol prints garbled)
    method: Printed as 30 for PVDF in Table 1, Pyroelectric Coefficient row.
    status: ground
    source: piezo-manual
    where: Table 1, Pyroelectric Coefficient row (PVDF column)
  - benchmark: acoustic_impedance
    label: Acoustic impedance, piezo film (PVDF)
    value: 2.7
    unit: 10^6 kg/(m2·s)
    scope: material
    conditions:
      basis: PVDF Film column of Table 2
    method: Printed as 2.7 for PVDF Film in Table 2, with the unit (10^6) kg/m2-sec.
    status: ground
    source: piezo-manual
    where: Table 2, Acoustic Impedance row
  - benchmark: specific_gravity
    label: Specific gravity, Kynar 1000 Series PVDF resin (not the film)
    value: 1.76
    value_high: 1.78
    bound: range
    unit: '-'
    scope: material
    conditions:
      grade: Kynar 1000 Series resin
      temperature: 23 °C
      test: D792
    method: Printed as 1.76 - 1.78 at D792 / 23 °C in the 1000 Series column. The printed units cell is blank, so the value is dimensionless.
    status: ground
    source: arkema-kynar-physical
    where: Physical properties table, Specific Gravity row, 1000 SERIES column
  - benchmark: molar_mass
    label: Molar mass of the PVDF repeat unit C2H2F2
    value: 64.0338
    unit: g/mole
    scope: material
    conditions:
      repeat_unit: C2H2F2
    method: NASA TM-2008-215490 Table IV prints the atomic mass units of the PVDF (Kynar) repeat unit as 64.0338 g/mole.
    status: calculated
    source: nasa-tm-2008-215490
    where: Table IV, Polyvinylidene fluoride PVDF (Kynar) row
  - benchmark: limiting_oxygen_index
    label: Limiting oxygen index, Kynar homopolymer resin
    value: 43
    unit: '-'
    scope: material
    conditions:
      standard: ASTM D2863
      grade: Kynar homopolymer resin
    method: Arkema prints a limiting oxygen index of 43 by ASTM D2863 for Kynar homopolymer resin. No unit is printed, so the value is a bare number.
    status: ground
    source: arkema-kynar-burning
    where: Burning Studies page, flammability paragraph
  - benchmark: chemical_resistance_ph_limit
    label: Chemical resistance limit by pH, Kynar homopolymer resin
    value: 12
    unit: pH
    scope: material
    conditions:
      temperature: ambient
      basis: long-term immersion ratings for worst-case conditions
    method: Arkema states that at ambient temperatures Kynar PVDF homopolymers are generally resistant to chemicals with a pH up to 12.
    status: ground
    source: arkema-kynar-chemical
    where: Chemical Resistance page, introduction
corrosion:
  - environment: Acids, weak bases, oxidants and halogens at ambient temperature
    headline: Arkema says Kynar PVDF resists these chemical classes at ambient temperature.
    effect: Arkema says Kynar PVDF resins are resistant to a wide range of chemicals, and that acids, weak bases, halogens, oxidants and salts pose little problem. Its homopolymers are generally resistant at ambient temperature up to pH 12. These statements are for the resin, not the piezo film.
    rating: low
    conditions:
      basis: Kynar resin statements; no test on piezo film
      temperature: ambient
    source: arkema-kynar-chemical
    where: Chemical Resistance page, introduction
  - environment: Humid air
    headline: Water absorption stays below 0.02 %.
    effect: The manual lists water absorption below 0.02 % H2O for PVDF and says the film resists moisture and most chemicals. No corrosion test on the film was found.
    rating: low
    conditions:
      basis: Table 1 water absorption; text on moisture resistance
    source: piezo-manual
    where: Table 1, Water Absorption row; Piezoelectric Film Properties section (text)
  - environment: Intense ultraviolet and nuclear radiation
    headline: The manual claims stability to intense ultraviolet and nuclear radiation, and Arkema reports the resin is essentially unchanged after a high gamma dose.
    effect: The manual says PVDF resists intense ultraviolet and nuclear radiation. Arkema says the resin tensile strength is 'essentially unchanged' after '100 megarads (Mrads)' of gamma radiation from a cobalt-60 source at 50 °C in high vacuum, and that impact strength and elongation are slightly reduced.
    rating: low
    conditions:
      dose: 100 megarads gamma, Kynar resin
      temperature: 50 °C
      atmosphere: high vacuum, 10-6 torr
    source: arkema-kynar-design
    where: Design Properties page, nuclear radiation paragraph; manual text on stability
  - environment: Atomic oxygen in low Earth orbit
    headline: A PVDF (Kynar) sample was measured on the MISSE 2 experiment, but its erosion yield is printed in power-of-ten form and is not recorded here.
    effect: NASA's MISSE 2 PEACE polymer experiment includes PVDF (Kynar), and Table I lists its atomic oxygen erosion yield from the flight samples. The printed value is in exponent form, so it is not recorded in this profile.
    rating: unknown
    conditions:
      platform: ISS, MISSE 2 PEACE, low Earth orbit
      table: Table I, MISSE 2 PEACE polymers erosion yield data
    source: nasa-tm-2008-215490
    where: Table I, Polyvinylidene fluoride PVDF (Kynar) row
  - environment: Long-term exposure at elevated temperature
    headline: Long-term heat permanently lowers the d33 constant.
    effect: The manual says the d33 constant decays permanently after long-term exposure to elevated temperatures, for film annealed at the temperature given in its Figure 23 caption. It says the film can be annealed to its operating or maximum storage temperature to gain long-term stability.
    rating: moderate
    conditions:
      annealing_temperature: 70 °C (Figure 23 caption)
      note: decay shown in Figure 23, no table values printed
    source: piezo-manual
    where: Temperature Effects section, Figure 23 and text
risks:
  hazards:
    - text: 'Fire: Arkema reports a limiting oxygen index of 43 by ASTM D2863 and a UL 94 V-0 burn rating for Kynar homopolymer resin. These are resin test results, not tests on the piezo film.'
      ghs: []
      source: arkema-kynar-burning
      where: Burning Studies page, flammability paragraphs
    - text: 'Fire standards: Arkema says Kynar and Kynar Flex resins meet or exceed NFPA 262 (UL 910 modified Steiner tunnel test for wire and cable), and that some grades pass NFPA 255.'
      ghs: []
      source: arkema-kynar-burning
      where: Burning Studies page, NFPA paragraphs
  failure_risks:
    - mode: Drift of the d33 constant after long-term heating
      trigger: Long-term exposure to elevated temperatures without annealing
      consequence: The manual says the d33 constant decays permanently after long-term exposure at elevated temperature (Figure 23).
      severity: moderate
      source: piezo-manual
      where: Temperature Effects section, Figure 23 and text
    - mode: Use or storage above the service limit
      trigger: Use or storage above 100 °C
      consequence: The manual says PVDF is not recommended for use or storage above 100 °C. Its copolymer is rated for a higher limit.
      severity: moderate
      source: piezo-manual
      where: Piezoelectric Film Properties section (text)
    - mode: Atomic oxygen erosion in low Earth orbit
      trigger: Exposure of PVDF (Kynar) to atomic oxygen in low Earth orbit, as on the MISSE 2 experiment
      consequence: NASA lists a measured erosion yield for PVDF (Kynar) on the MISSE 2 experiment. The value is printed in exponent form and is not recorded here.
      severity: moderate
      source: nasa-tm-2008-215490
      where: Table I, PVDF row
    - mode: Electrical pickup from exposed electrodes
      trigger: Electrodes left exposed in a high electromagnetic or RFI environment
      consequence: The manual says the sensor can be sensitive to electromagnetic radiation when electrodes are exposed, and that good shielding techniques exist.
      severity: low
      source: piezo-manual
      where: Piezoelectric Film Properties section (text)
  side_effects: []
  handling:
    - text: Keep the film below 100 °C in use and storage, since the manual says PVDF is not recommended above that temperature.
      source: piezo-manual
      where: Piezoelectric Film Properties section (text)
    - text: Shield exposed electrodes in high EMI or RFI environments.
      source: piezo-manual
      where: Piezoelectric Film Properties section (text)
  mitigations:
    - text: Anneal the film to its highest operating or maximum storage temperature to stabilise long-term piezoelectric properties, as the manual describes.
      source: piezo-manual
      where: Temperature Effects section (text)
uses:
  - application: electronics-and-chips
    device: Piezo polymer sensors built on silicon chips
    example: The manual says piezoelectric polymers can be spin-coated onto silicon, polarised in place, metallised in pattern arrays and interconnected with integrated circuits on the chip. No commercial product is named.
    source: piezo-manual
    where: Sensors on Silicon, under Future Applications
  - application: optics-and-cameras
    device: Thermal camera sensors
    example: Wikipedia says thin films of PVDF are used in some newer thermal camera sensors, using the pyroelectric effect. The manual says PVDF 'strongly absorbs infrared energy' in the wavelength band that matches human body heat.
    source: wikipedia-pvdf
    where: Properties section
  - application: electronics-and-chips
    device: Impact detector for high-speed particles in space
    example: The manual says the sensor has been used to detect the impact of high-speed particles in space. Its bibliography lists PVDF dust detector papers by Tuzzolino (entries F41 and F49).
    source: piezo-manual
    where: Dynamic Range section (text); Appendix B bibliography
  - application: structures
    device: Vibration damping for space-based structures (proposed)
    example: The manual lists the reduction of harmful vibrations in space-based structures among its future applications.
    source: piezo-manual
    where: Active Vibration Damping, under Future Applications
supply:
  - subject: Fluorspar (calcium fluoride), feedstock for fluorine chemicals
    abundance: USGS says the United States was 100% net import reliant for fluorspar in 2025, and China held 110,000 thousand t of the 330,000 thousand t world reserves (as printed).
    producers:
      - country: China
        share_percent: 60
        year: 2025
      - country: Mexico
        share_percent: 15
        year: 2025
      - country: Mongolia
        share_percent: 15
        year: 2025
      - country: South Africa
        share_percent: 4.1
        year: 2025
      - country: Vietnam
        share_percent: 1.6
        year: 2025
      - country: Spain
        share_percent: 1.4
        year: 2025
    critical_lists: []
    recycling: USGS says primary aluminum producers recycle HF and fluorides from smelting operations.
    substitutes: []
    source: usgs-fluorspar-2026
    where: 'World Mine Production and Reserves table, 2025 column (thousand t: China 6,000; Mexico 1,500; Mongolia 1,500; South Africa 410; Vietnam 160; Spain 140; world total 10,000). Shares calculated by Space Mushroom against the printed world total.'
  - subject: Hydrogen fluoride (feedstock for fluoropolymers)
    abundance: USGS says aqueous hydrogen fluoride is the primary feedstock for virtually all fluorine-bearing chemicals, particularly refrigerants and fluoropolymers.
    producers: []
    critical_lists: []
    substitutes: []
    source: usgs-fluorspar-2026
    where: Domestic Production and Use, first paragraph
documents:
  - title: Piezo Film Sensors Technical Manual, Measurement Specialties Inc., P/N 1005663-1 REV B (1999)
    type: datasheet
    url: https://cdn.sparkfun.com/assets/d/a/a/b/b/Piezo_Film_Sensors_Technical_Manual.pdf
    year: 1999
  - title: Banks, Backus and de Groh, Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit, NASA/TM-2008-215490
    type: report
    url: https://ntrs.nasa.gov/citations/20090011780
    year: 2008
  - title: 'USGS, Mineral Commodity Summaries 2026: Fluorspar'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
  - title: Arkema Kynar, contact physical and mechanical properties
    type: datasheet
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/contact-physical-and-mechanical-properties/
    year: 2026
  - title: Arkema Kynar, burning studies
    type: datasheet
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/burning-studies/
    year: 2025
gaps:
  - 'No safety data sheet for the piezo film and no PubChem GHS record for PVDF or vinylidene fluoride could be read: the PubChem page returned a reCAPTCHA check. The hazard entries are Arkema''s fire-test statements for PVDF resin.'
  - NASA TM-2008-215490 Table I gives the PVDF erosion yield in power-of-ten form, so the value is not recorded here. The MISSE 2 result is cited for flight exposure only.
  - Volume resistivity is printed in the manual in exponent form, so it is not recorded.
  - Absolute permittivity is printed in exponent form, so only the relative permittivity is recorded.
  - The g33 stress constant appears in Table 1 with a unit column that could not be read reliably from the PDF text, so it is not recorded.
  - No Curie temperature for PVDF was found in the manual or in the Wikipedia article.
  - No melting temperature for piezo film was found in the manual. Wikipedia quotes one, but Wikipedia is used here only for composition and history, so it is not recorded.
  - Outgassing, UV retention and thermal-vacuum data for the piezo film were not found. The manual gives qualitative statements on UV and radiation only.
  - The Tuzzolino PVDF dust detector papers listed in the manual bibliography (entries F41 and F49) were not opened, and no open paper on PVDF impact detectors in orbit was found.
  - The web search budget for this run was used up before further open papers on piezoelectric PVDF properties could be found, so the value sources are the 1999 manual and the Arkema resin pages.
  - Critical-mineral status of fluorspar is not printed in the USGS 2026 chapter read.
  - No producer shares or plant locations were found for PVDF resin or piezo film.
  - Chemical resistance is given only by chemical class and by a pH limit for the resin. No per-chemical rating for the piezo film was found.
  - The piezo constants are typical values from a 1999 manual. No current film maker datasheet was found.
  - The Arkema values (specific gravity, radiation and chemical resistance, fire tests) are for Kynar resins, not for the piezo film, and the film may differ.
sources:
  piezo-manual:
    title: Piezo Film Sensors Technical Manual
    id: Measurement Specialties, Inc., Sensor Products Division, P/N 1005663-1 REV B, 02 APR 99
    url: https://cdn.sparkfun.com/assets/d/a/a/b/b/Piezo_Film_Sensors_Technical_Manual.pdf
    year: 1999
    kind: handbook
    license: manufacturer manual, linked not reproduced
  wikipedia-pvdf:
    title: Polyvinylidene fluoride, Wikipedia
    id: Wikipedia article, Introduction, Processing and Properties sections
    url: https://en.wikipedia.org/wiki/Polyvinylidene_fluoride
    year: 2026
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  usgs-fluorspar-2026:
    title: 'Mineral Commodity Summaries 2026: Fluorspar'
    id: USGS MCS 2026, fluorspar chapter
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
    kind: report
    license: US government work
  nasa-tm-2008-215490:
    title: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit
    id: NASA/TM-2008-215490 (Banks, Backus and de Groh, 2008), NTRS 20090011780
    url: https://ntrs.nasa.gov/citations/20090011780
    year: 2008
    kind: report
    license: NASA public document
  arkema-kynar-burning:
    title: Kynar PVDF, burning studies, Arkema
    id: Arkema HPP Kynar family, burning studies page
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/burning-studies/
    year: 2025
    kind: datasheet
    license: manufacturer web page, linked not reproduced
  arkema-kynar-chemical:
    title: Kynar PVDF, chemical resistance and fuel resistance, Arkema
    id: Arkema HPP Kynar family, chemical resistance page
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/chemical-resistance-fuel-resistance/
    year: 2025
    kind: datasheet
    license: manufacturer web page, linked not reproduced
  arkema-kynar-design:
    title: 'Kynar PVDF, design properties: solubility and irradiation, Arkema'
    id: Arkema HPP Kynar family, design properties page
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/design-properties-solubility-irradiation/
    year: 2025
    kind: datasheet
    license: manufacturer web page, linked not reproduced
  arkema-kynar-physical:
    title: Kynar PVDF, contact physical and mechanical properties, Arkema
    id: Arkema HPP Kynar family, physical and mechanical properties tables
    url: https://hpp.arkema.com/en/product-families/kynar-fluoropolymer-family/contact-physical-and-mechanical-properties/
    year: 2026
    kind: datasheet
    license: manufacturer web page, linked not reproduced
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 23
  unreachable: 1
  caveats: 4
  note: Values read by an AI assistant on 2026-11-01 from the 1999 Measurement Specialties manual (PDF text), NASA TM-2008-215490 (NTRS PDF), the USGS 2026 fluorspar chapter and three Arkema Kynar pages. PubChem returned a reCAPTCHA check and was not used. The web search budget for the run was used up, so no further sources were added. Wikipedia is used for uses text only. The Arkema values are for Kynar resins, not the piezo film.
story:
  recipe:
    line: Piezo film is a sheet of polyvinylidene fluoride (PVDF), a linear polymer whose repeat unit is C2H2F2. The manual says PVDF resin pellets are melt-extruded into a sheet, the sheet is stretched to about one-fifth of its extruded thickness so the chains pack into the beta phase, the film is poled in a very high electric field to align the crystallites, and metal electrodes are then deposited on both faces.
    parts:
      - name: Carbon
        symbol: C
        role: Two carbon atoms per repeat unit form the CH2 and CF2 backbone.
        source: nasa-tm-2008-215490
        where: Table V, PVDF (Kynar) row (NC = 2)
      - name: Hydrogen
        symbol: H
        role: Two hydrogens sit on the CH2 group of each repeat unit.
        source: nasa-tm-2008-215490
        where: Table V, PVDF (Kynar) row (NH = 2)
      - name: Fluorine
        symbol: F
        role: Two fluorines sit on the CF2 group of each repeat unit, which makes the film highly polar.
        source: nasa-tm-2008-215490
        where: Table V, PVDF (Kynar) row (NF = 2)
  risk_groups:
    - title: For people
      lead: No classification for the piezo film was found. The only hazard data read are Arkema's fire-test statements for PVDF resin.
      level: 1
      verdict: No GHS classification read
      points:
        - label: Fire
          line: Arkema reports a limiting oxygen index of 43 by ASTM D2863 and a UL 94 V-0 burn rating for Kynar homopolymer resin.
        - label: Monomer
          line: No hazard record for the vinylidene fluoride monomer was read, because the PubChem page returned a reCAPTCHA check.
    - title: If it fails
      lead: Heat is the main limit. The manual says PVDF is not recommended for use or storage above 100 °C.
      level: 2
      points:
        - label: Heat
          line: Long-term exposure at elevated temperature permanently lowers the d33 constant, as the manual shows in Figure 23.
        - label: Space
          line: NASA lists a measured atomic oxygen erosion yield for PVDF (Kynar) on the MISSE 2 experiment. The value is printed in exponent form and is not recorded here.
  why: 'Piezo film is a thin, flexible PVDF sheet. When it is stressed it produces an electric charge, and when a field is applied it changes shape. The manual says PVDF is more highly piezoelectric than nylon, PVC or the other polymers it compares, and that the film is light, tough and easy to glue. Its use is limited by heat: the manual says PVDF is not recommended for use or storage above 100 °C, and its d33 constant drops after long-term heating.'
  uses:
    - where: Sensors on silicon
      line: The manual says PVDF can be spin-coated onto silicon, polarised in place, metallised and wired to integrated circuits on the same chip.
    - where: Thermal camera sensors
      line: Wikipedia says thin PVDF films are used in some newer thermal camera sensors. The effect used is pyroelectric, which means the film responds to a change in temperature.
    - where: Particle impacts in space
      line: The manual says piezo film has been used to detect the impact of high-speed particles in space, and its bibliography lists PVDF dust detector papers by Tuzzolino.
    - where: Vibration damping (proposed)
      line: The manual lists reducing harmful vibrations in space-based structures among its future applications.
  can_do:
    - label: Sense a force
      benchmark: piezo_d31
      value: 23 (10^-12 m/V, stretch direction)
      line: The d31 strain constant is 23 in units of 10^-12 m/V in the stretch direction, and the d33 value is -33 in the thickness direction. The manual calls piezo film a weak transmitter compared with ceramics, but a very sensitive receiver.
    - label: Take a high stress
      benchmark: stress_without_failure
      value: 350 MPa
      line: The manual reports that a 52 µm film was stressed to approximately 350 MPa in the stretch direction without failure.
    - label: Work up to 100 °C
      benchmark: max_service_temp
      value: 100 °C
      line: The manual says PVDF is not recommended for use or storage above 100 °C. Its copolymer is rated for a higher limit.
    - label: Resist moisture
      benchmark: moisture_absorption
      value: below 0.02 %
      line: The manual prints water absorption of below 0.02 % H2O for PVDF, and says the film is highly stable against moisture.
  compare: 'Piezo film is a light, flexible alternative to piezo ceramics. Table 2 of the manual compares PVDF film with PZT and BaTiO3 ceramics: the film has a lower density, a much lower relative permittivity, a smaller d31 constant and a much lower acoustic impedance, but a higher voltage output for the same force input. The Kynar resin that the film is made from has a specific gravity of 1.76 to 1.78 (Arkema), which is close to the film density.'
  compare_rows:
    - label: Density
      benchmark: density
    - label: Piezo strain constant d31
      benchmark: piezo_d31
    - label: Acoustic impedance
      benchmark: acoustic_impedance
  handling:
    - Keep the film below 100 °C in use and storage. The manual says PVDF is not recommended above that temperature.
    - Shield exposed electrodes in high EMI or RFI environments, because the sensor can respond to electromagnetic radiation.
    - Anneal the film to its operating or maximum storage temperature to stabilise d33 over long periods, as the manual describes.
    - Check the current safety data sheet from the film supplier before handling. None was found for this film.
  good_for:
    - 'Light, flexible sensing: a density of 1.78 g/cm3 and an acoustic impedance of 2.7 (10^6 kg/(m2·s)), closer to water than ceramics.'
    - 'Impact sensing over a wide range: a 52 µm film took approximately 350 MPa in the stretch direction without failure.'
    - 'Known space exposure: NASA lists PVDF (Kynar) on the MISSE 2 experiment in low Earth orbit, with an erosion yield printed in Table I.'
  watch_out:
    - 'Heat: not recommended above 100 °C, and long-term heating permanently lowers d33 (Figure 23).'
    - Atomic oxygen erodes PVDF in low Earth orbit. The MISSE 2 erosion value is not recorded here, so exterior use needs a rate allowance.
    - Weak as a transmitter compared with ceramics, especially at resonance, according to the manual.
    - No outgassing or UV retention data for the film were found.
  verdict: 'PVDF piezo film is a light, flexible, piezoelectric polymer: density 1.78 g/cm3, d31 of 23 (10^-12 m/V) and a 100 °C service limit in the manual. It suits sensors and impact detectors where weight and flexibility matter more than heat resistance. Space exposure data come from a single MISSE 2 flight result.'