Neural Noise

Transparent, metal-free PEDOT:PSS neural interfaces for electrophysiology and two-photon imaging

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  • Transparent, metal-free PEDOT:PSS neural interfaces enable simultaneous low-noise electrophysiology and artifact-free two-photon imaging at the same site.1
  • Metal-free design improves optical access and recording quality.1
  • Combined electrophysiology and imaging supports causal experiments in neural circuits.1 1

Weekly enrichment (2026-07-20)

  • The array is fully transparent, with both the recording electrodes and the interconnect lines made of PEDOT:PSS; earlier “transparent” implants still used opaque metal, graphene, or carbon-nanotube interconnects that obstructed the two-photon field of view.23
  • The device is a 30-channel electrode array with 20 × 20 µm² recording sites fabricated on a 25 µm flexible PET substrate, whose Young’s modulus is close to that of PEDOT:PSS to reduce mechanical mismatch with cortical tissue.2
  • A formamide, phosphoric acid, and ethylene glycol (FPE) post-treatment cut electrochemical impedance to about 45.8 kΩ at 1 kHz even at the small 20 × 20 µm² site size, surpassing prior metal-free transparent interfaces.24
  • FPE treatment raised the volumetric capacitance of PEDOT:PSS from 0.436 F/cm³ (pristine) to 30.4 F/cm³, on par with values reported for PEDOT:PSS supercapacitor films.2
  • The electrodes captured extracellular action potentials and low-noise local field potentials, and delivered stable RMS noise (lower than a Pt-black reference array) whether the two-photon laser equipment was on or off, i.e., no laser-induced photoelectric artifacts across the 358–900 nm excitation range.2
  • In vivo the array supported artifact-free two-photon imaging of vasculature and neurons together with reliable electrical recording, and biocompatibility tests showed negligible cytotoxicity or immune response.24
  • For context, an earlier transparent PEDOT:PSS microelectrode array (2022) reached >75% visible-light transparency at 380 nm film thickness and single-unit recordings with a signal-to-noise ratio of 7.7 (17.7 dB), illustrating how the new fully-transparent-interconnect design advances the field.5

Footnotes

  1. https://news.google.com/rss/articles/CBMiX0FVX3lxTE8xUWZ2aVlIaWVWTGxzS3NpUWhzeDRkaVBnZ2dtNnZRQXFQY3BlbnEwTW1XTGRmTnUtdC1tZnpuMEtYdFJIeGJNN05xdmJ1MzFpV0hEUHVidWZGaW5XZ3Jj?oc=5 ↩ ↩2 ↩3 ↩4

  2. https://www.nature.com/articles/s41467-025-59303-2 ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  3. https://doi.org/10.1038/s41467-025-59303-2 ↩

  4. https://pubmed.ncbi.nlm.nih.gov/40301389/ ↩ ↩2

  5. https://www.nature.com/articles/s41378-022-00434-7 ↩

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