Electrical Transport — Bulk protonic conductivity in a cephalopod structural protein

6 measurement groups · 18 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Wild-type reflectin A1 thin film on SiO2/Si with gold electrodes · Thin Film

Bias limited to +/-1.5 V; dry RH <50% and humidified RH 90%; ambient controlled humidity.

Atmosphere: ambient controlled humidity
Geometry: 50 um length, 250 um width, 1.3 um thickness for Supplementary Fig. 5; paired electrodes 100 um wide by 400 um long with 50 um separation
Context: pristine wild-type reflectin film compared with dry film and no-bridging-material control
Measurement source: 597 · Results · Supplementary Figure 5

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Dry-film current level	on the order of a few picoamps; similar to no bridging material	—	—	Text Qualitative	597 · Results · Supplementary Figure 5
Gold-contact current density at 90% RH and 1.5 V	0.6(+0.2) x 10^-2 A cm^-2	—	+/-0.2 x 10^-2 A cm^-2	Text Exact Reported	597 · Results · Supplementary Figure 5

Wild-type reflectin A1 thin film on glass with gold electrodes · Thin Film

A.c. impedance in humidified H2O or D2O vapour at RH 90%; fitted to Ci-(Rb||Cb) equivalent circuit.

Atmosphere: H2O vapour or D2O vapour, 90% RH
Geometry: Figure 1 isotope device: 50 um length, 25,000 um width, 4.6 um thickness; EIS devices on glass had 100 um inter-electrode separation
Context: pristine wild-type reflectin thin film
Measurement source: 597 · Results · Figure 1

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
EIS conductivity in D2O vapour at 90% RH	0.6(+0.3) x 10^-4 S cm^-1	—	+/-0.3 x 10^-4 S cm^-1	Text Exact Reported	598 · Results · Figure 1
EIS conductivity in H2O vapour at 90% RH	1.0(+0.5) x 10^-4 S cm^-1	—	+/-0.5 x 10^-4 S cm^-1	Text Exact Reported	597 · Results · Figure 1
Conductivity decrease on H2O to D2O exchange	decreased by 40%	—	—	Text Rounded Reported	598 · Results · Figure 1

Wild-type reflectin A1 thin film on glass with gold electrodes · Thin Film

Nyquist plots from 30 to 65 deg C in 5 deg C increments at RH 90%; 500 mV a.c. applied voltage; 30 min dwell for thermal stability.

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Proton transport activation energyMarked as a best value within this paper	Ea = 0.22(+0.05) eV	—	+/-0.05 eV	Text Exact Reported	599 · Results · Figure 4
Average proton conductivity at 65 deg C	1.2(+1) x 10^-3 S cm^-1	—	+/-1 x 10^-3 S cm^-1	Text Exact Reported	599 · Results · Figure 4
Peak proton conductivity at 65 deg CMarked as a best value within this paper	2.6 x 10^-3 S cm^-1 at 65 deg C and RH 90%	—	—	Text Exact Reported	599 · Results · Figure 4

Wild-type reflectin A1 thin film with palladium hydride electrodes · Thin Film

Measured at RH 60-90% and +/-1.5 V; Pd converted to PdHx in situ by H2 exposure.

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Humidity dependence of PdHx-contact current	current increases as RH is raised from 60% to 90%	—	—	Caption Qualitative	598 · Figure caption · Figure 2
Wild-type reflectin current density with PdHx contacts	8.2(+5.9) x 10^-2 A cm^-2 at 1.5 V	—	+/-5.9 x 10^-2 A cm^-2	Text Exact Reported	598 · Results · Figure 2

DE->A mutant reflectin A1 thin film with PdHx electrodes · Thin Film

RH 90%, +/-1.5 V; forward and reverse scans shown.

Atmosphere: humidified; PdHx contacts
Geometry: All comparison devices 50 um length; widths 265, 210, 220 um and thicknesses 0.8, 1.0, 1.1 um for wild-type, DE->A, and Random respectively
Context: pristine wild-type target compared with mutant protein controls
Measurement source: 599 · Figure caption · Figure 3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
DE->A mutant current density with PdHx contacts	0.9(+0.2) x 10^-2 A cm^-2 at 1.5 V	—	+/-0.2 x 10^-2 A cm^-2	Text Exact Reported	598 · Results · Figure 3
Random mutant current density with PdHx contacts	1.7(+0.3) x 10^-2 A cm^-2 at 1.5 V	—	+/-0.3 x 10^-2 A cm^-2	Text Exact Reported	599 · Results · Figure 3

Wild-type reflectin A1 three-terminal protonic transistor · Thin Film

IDS versus VDS measured while modulating VGS from -10 to +10 V; RH 90%; VDS up to 1.5 V.

Atmosphere: humidified, RH 90%; PdHx contacts formed in 5% H2/95% Ar
Geometry: Figure 5 device: 50 um length, 267 um width, 1.1 um thickness; SiO2 gate oxide ca. 900 A
Context: pristine wild-type reflectin channel
Measurement source: 600 · Results · Figure 5

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Typical IDS at VDS = 1.5 V and VGS = -10 V	approximately 330 nA from Figure 5b	—	—	Figure Axis Approximate	600 · Figure · Figure 5b
Typical IDS at VDS = 1.5 V and VGS = +10 V	approximately 195 nA from Figure 5b	—	—	Figure Axis Approximate	600 · Figure · Figure 5b
Free proton concentration at VGS = 0 VMarked as a best value within this paper	nH+ = 10.6(+6.1) x 10^16 cm^-3	—	+/-6.1 x 10^16 cm^-3	Text Exact Reported	600 · Results · Figure 5
Effective proton mobilityMarked as a best value within this paper	mu_H+ = 7.3(+2.8) x 10^-3 cm2 V^-1 s^-1	—	+/-2.8 x 10^-3 cm2 V^-1 s^-1	Text Exact Reported	600 · Results · Figure 5
Gate leakage current	negligible leakage currents; Supplementary Fig. 14 shows roughly -5 to +3 nA over -10 to +10 VGS	—	—	Visual Estimate Approximate	600 · Results · Supplementary Figure 14
Conductivity calculated from transistor IDS-VDS curves	1.1(+0.3) x 10^-4 S cm^-1	—	+/-0.3 x 10^-4 S cm^-1	Text Exact Reported	600 · Results · Figure 5