Data from: Integrated hierarchical surface restructuring of assembled electrode arrays for next-generation neural interfaces
Data files
Jun 18, 2026 version files 1.39 MB
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Data.xlsx
751.88 KB
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README.md
8.28 KB
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Unformatted_-_CVCO2.csv
228.08 KB
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Unformatted_-_CVNoCO2.csv
298.40 KB
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Unformatted_-_EISCO2.csv
36.55 KB
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Unformatted_-_EISNoCO2.csv
46.21 KB
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Unformatted_-_Paper_DOE.csv
22.16 KB
Abstract
Neurostimulation devices rely on electrode arrays to deliver targeted electrical stimulation for modulating nerve activity. Enhancing stimulation specificity, device battery and energy efficiency, and device miniaturization requires low-profile electrodes with exceptional electrochemical performance. Hierarchical Surface Restructuring (HSR™), a femtosecond laser-based electrode surface treatment technology, enables these improvements by significantly increasing the electrochemically active surface area of the electrode contacts through the formation of highly textured, multi-scale architectures. Although HSR™ offers substantial potential to enable both high-performance electrodes and further miniaturization of electrode arrays, its broader adoption in medical device manufacturing has been limited by cost considerations and the inherent complexities of integrating new surface modification steps into established production workflows. This study investigates the feasibility of applying HSR™ technology to commercially available Pt-10Ir paddle-type electrode arrays and, for the first time, demonstrates that HSR™ can be implemented as a stand-alone, post-fabrication surface modification process that is compatible with existing device geometries and material constraints. This advancement represents a significant step toward broader adoption of HSR™ by medical device manufacturers and demonstrates its overall manufacturing viability. The process developed in this study circumvents key barriers to industrial implementation by enabling HSR™ to be seamlessly integrated into existing production lines as a post-fabrication surface modification step, thereby eliminating the need for major or costly process changes. The morphology, electrochemical performance, and processing efficiency of the restructured electrodes were systematically characterized. HSR™ enhanced key electrochemical metrics—including charge storage capacity, specific capacitance, and impedance—by up to two orders of magnitude, while maintaining short processing times and full compatibility with the device’s geometry and constituent materials. These findings demonstrate the potential for HSR™ to be seamlessly integrated into existing manufacturing workflows as a post-fabrication step, providing a scalable and cost-effective approach for enhancing the electrochemical performance of neurostimulation electrode arrays. Furthermore, in-operando CO₂-snow-assisted processing was shown to be equally compatible with established production lines, improving electrode stability and surface cleanliness without necessitating any upstream process modifications.
Dataset DOI: 10.5061/dryad.mkkwh71fb
Description of the data and file structure
This data is collected as part of a study to evaluate the feasibility of applying femtosecond laser Hierarchical Surface Restructuring (HSR™) to fully assembled Pt-10Ir paddle-type electrode arrays used for spinal cord stimulation applications. The study evaluates whether HSR™ can be used as a post-fabrication surface modification process to improve electrochemical performance while remaining compatible with the geometry, polymer insulation, and material constraints of assembled electrode arrays. Specifically, this data includes design-of-experiment summary values, cyclic voltammetry, and electrochemical impedance spectroscopy results for electrode contacts restructured at 3 different laser fluences:
3.86 J/cm²
5.96 J/cm²
8.63 J/cm²
The surface processing conditions included:
Non-CO2: HSR™ treatment performed without CO2-snow-assisted processing.
Tandem-CO2: HSR™ treatment performed with CO2-snow-assisted processing applied simultaneously with femtosecond laser restructuring.
Unrestructured control: Electrode contacts that were not laser restructured and were used as baseline controls.
Each paddle array contains 16 Pt-10Ir electrode contacts. Four channels were left unrestructured as controls, and three sets of four channels were restructured at the three fluence levels listed above. The study was designed to evaluate the effect of laser fluence and tandem CO2-snow-assisted processing on electrochemical performance, including charge storage capacity, impedance, and specific capacitance. Processing time was also tracked to assess the practicality of applying HSR™ to fully assembled electrode arrays.
Files and variables
File: Data.xlsx
Description: The spreadsheet contains design-of-experiment summary data, cyclic voltammetry data, and electrochemical impedance spectroscopy data for HSR™-treated and unrestructured Pt-10Ir paddle electrode array contacts.
Sheet: Paper DOE (and Unformatted_-_Paper_DOE.csv)
This sheet contains the design-of-experiment summary table for the paddle electrode array study. It summarizes the electrode channel layout, applied processing condition, laser fluence, electrochemical performance metrics, and processing time values for the Non-CO2 and Tandem-CO2 paddle arrays. The sheet includes individual channel-level values as well as averaged values for each group of four channels.
The sheet is divided into two paddle/processing groups:
Non-CO2: Electrode contacts restructured without tandem CO2-snow-assisted processing.
Tandem-CO2: Electrode contacts restructured with tandem CO2-snow-assisted processing.
For each paddle group, Channels 1-4 are unrestructured control electrodes. Channels 5-8 were restructured at 3.86 J/cm², Channels 9-12 were restructured at 5.96 J/cm², and Channels 13-16 were restructured at 8.63 J/cm².
Paddle: Paddle condition, either Non-CO2 or Tandem-CO2.
Channel: Electrode contact number on the 16-channel paddle array.
Fluence (J/cm^2): Laser fluence used for HSR™ processing. Note that fluences are left blank for channels 1-4 of each group, because these are unrestructured and did not undergo laser treatment.
Total CSC (mC/cm^2): Total charge storage capacity normalized by electrode area.
CSC StdDv: Standard deviation associated with the CSC measurement.
Capacitance (uF/mm²): Specific capacitance normalized by electrode area.
Capacitance StdDv: Standard deviation associated with the specific capacitance measurement.
AVERAGES: Summary values averaged across the four corresponding channels in each condition
Process Time (s): Processing time per electrode channel.
Time/Area (s/mm²): Processing time normalized by treated surface area.
Sheet: CV NoCO2 (and Unformatted_-_CVNoCO2.csv)
This sheet contains cyclic voltammetry data for electrode contacts restructured without tandem CO2-snow-assisted processing, along with unrestructured control electrodes. CV testing was performed to evaluate electrochemical performance, especially charge storage behavior. The associated manuscript describes CV testing over a potential window of approximately -0.6 V to 0.8 V vs. Ag/AgCl. The area enclosed by the CV curve was used to calculate total charge storage capacity.
Results are grouped by laser fluence and replicate cycle/contact group.
XY (V vs. Ag/AgCl): Applied potential during the CV sweep, in volts versus Ag/AgCl.
Cycle1, Cycle2, Cycle3 (A/cm²): Replicate current-density values, in amperes per square centimeter.
Average (A/cm²): Mean of the three replicate current-density measurements, in amperes per square centimeter.
StdDev (A/cm²): Standard deviation of the three replicate current-density measurements, in amperes per square centimeter.
Unres: Unrestructured control electrode condition. No units.
Sheet: EIS NoCO2 (and Unformatted_-_EISNoCO2.csv)
This sheet contains electrochemical impedance spectroscopy data for electrode contacts restructured without tandem CO2-snow-assisted processing, along with unrestructured control electrodes. EIS was used to characterize impedance behavior over a frequency range and to support the extraction of specific capacitance by fitting the results to an equivalent Randles circuit model. Impedance at 1 kHz is particularly relevant for neural interfacing and stimulation applications.
Results are grouped by laser fluence and experiment repetition (cycles).
XY (Hz): Frequency, in hertz.
Cycle1, Cycle2, Cycle3 (ohms): Replicate impedance magnitude values, in ohms.
Average (ohms): Mean impedance value of the three replicate measurements, in ohms.
StdDev (ohms): Standard deviation of the three replicate impedance measurements, in ohms.
Unres: Unrestructured control electrode condition. No units.
Sheet: CV CO2 (and Unformatted_-_CVCO2.csv)
This sheet contains cyclic voltammetry data for electrode contacts restructured with tandem CO2-snow-assisted processing. In this condition, CO2-snow-assisted processing was applied simultaneously with femtosecond laser restructuring. The purpose of this processing condition was to evaluate whether in-operando CO2-snow-assisted HSR™ could improve surface cleanliness and stability while maintaining strong electrochemical performance.
Results are grouped by laser fluence and repetitions. Unrestructured electrodes are not included because CO2 processing has no effect on their performance.
XY (V vs. Ag/AgCl): Applied potential during the CV sweep, in volts versus Ag/AgCl.
Cycle1, Cycle2, Cycle3 (A/cm²): Replicate current-density values for the corresponding fluence, in amperes per square centimeter.
Average (A/cm²): Mean of the three replicate current-density measurements, in amperes per square centimeter.
StdDev (A/cm²): Standard deviation of the three replicate current-density measurements, in amperes per square centimeter.
Sheet: EIS CO2 (and Unformatted_-_EISCO2.csv)
This sheet contains electrochemical impedance spectroscopy data for electrode contacts restructured with tandem CO2-snow-assisted processing. EIS was used to compare the impedance behavior of CO2-assisted HSR™ electrodes across the tested fluence levels and to support specific capacitance calculations through equivalent circuit fitting.
Results are grouped by laser fluence and repetitions.
XY (Hz): Frequency, in hertz.
Cycle1, Cycle2, Cycle3 (ohms): Replicate impedance magnitude values, in ohms.
Average (ohms): Mean impedance value of the replicate measurements, in ohms.
StdDev (ohms): Standard deviation of the replicate impedance measurements, in ohms.
For data included in each sheet, findings are analyzed and synthesized in greater detail in the associated publication.
Unformatted CSV files
These files contain the same content as the corresponding sheets in the Excel file above, but are contained in unformatted, comma-separated .csv files
