pith. sign in

arxiv: 2604.25830 · v1 · submitted 2026-04-28 · ❄️ cond-mat.soft

Universal material basis for biocompatible printed electrolytes in Organic Electrochemical Transistors

Moritz Flemming , Paul Zechel , Rakesh R. Nair , Emil Mahnke , Markus L\"offler , Alyna Ong , Bernd Rellinghaus , Lukas M. Eng
show 2 more authors
Karl Leo Hans Kleemann
This is my paper

Pith reviewed 2026-05-07 14:35 UTC · model grok-4.3

classification ❄️ cond-mat.soft
keywords biocompatible electrolytesorganic electrochemical transistorsUV-curable electrolytesscreen printingprinted OECTsionic liquid electrolytesflexible electronicsbiosensors
0
0 comments X

The pith

A biocompatible electrolyte material enables fully printed OECTs on leaves that last over 30 days in air.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper shows how a new material basis, when mixed with an ionic liquid, creates an electrolyte suitable for organic electrochemical transistors using only biocompatible components. This mix can be adjusted for easy printing by inkjet or screen methods and then hardened by UV light into a solid form. As a result, the printed devices can keep working in regular air for more than a month, and the authors demonstrate a complete transistor printed on a leaf. Readers would be interested because this opens doors to safe, low-cost electronics that can connect with living systems or be made on flexible natural surfaces without toxic chemicals.

Core claim

The central discovery is a novel material basis for OECT electrolytes that contains only biocompatible materials when combined with an ionic liquid. This basis supports rheological tuning for inkjet and screen printing, followed by UV curing to form solid-state structures. The resulting devices exhibit extended lifetimes, operating in ambient air for over 30 days after fabrication, with a demonstration of a fully screen-printed biocompatible transistor on a leaf substrate.

What carries the argument

The novel material basis for the biocompatible electrolyte, which allows rheological adjustments and UV-curing to enable printing and solid-state transition.

Load-bearing premise

The material basis remains biocompatible and maintains performance without introducing toxicities or incompatibilities across different substrates and printing conditions.

What would settle it

Demonstrating that the fully printed OECT on a leaf substrate fails to operate after 30 days in ambient air or shows signs of toxicity in biocompatibility tests would disprove the central claim.

read the original abstract

Organic Electrochemical Transistors (OECTs) stand out for their interplay between ionic and electronic conduction, making them ideal analogues to biological synapses for neuromorphic computing and biosensing applications. Furthermore, they can be printed into integrated circuits on flexible substrates, enabling low-cost and high-throughput fabrication of complete electronic systems. However, most OECT electrolytes for integrated circuits still lack biocompatibility and suffer from rheology-related printing challenges. This paper presents a novel material basis that can be combined with an ionic liquid to fabricate an electrolyte for OECTs that only contains biocompatible materials. It allows rheological adjustments to enable the use of electrolyte in both inkjet and screen printing. Furthermore, the electrolyte is UV-curable, enabling it to transition into solid-state structures after printing. Extended ink and device lifetimes for screen-printed structures enable the fabrication of advanced OECTs that can operate in ambient air for over 30 days after fabrication. Ultimately, a fully screen-printed transistor using only biocompatible materials on a leaf substrate is shown

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript introduces a biocompatible, rheology-tunable, UV-curable electrolyte material basis for organic electrochemical transistors (OECTs) that combines with an ionic liquid to enable both inkjet and screen printing. The electrolyte transitions to a solid state post-printing, supports extended ink and device lifetimes, and allows OECT operation in ambient air for over 30 days. The work culminates in a demonstration of a fully screen-printed, all-biocompatible OECT fabricated on a leaf substrate.

Significance. If the reported stability and functionality hold under the stated conditions, the material platform addresses critical barriers to printable, biocompatible OECTs for biosensing and neuromorphic applications. The combination of printability across techniques, UV-induced solidification, and >30-day ambient stability on an unconventional natural substrate represents a practical advance toward sustainable, flexible bioelectronics.

major comments (2)
  1. [Abstract and device characterization] The central stability claim (>30 days ambient operation) is load-bearing for the headline result, yet the abstract and summary provide no quantitative metrics (e.g., transconductance retention, on/off current ratio, or threshold voltage drift) with error bars or replicate counts. Device characterization sections should include time-dependent electrical data with statistical controls to substantiate the lifetime assertion.
  2. [Materials and methods] The assertion of a 'universal' biocompatible material basis requires explicit validation that the formulation introduces no unstated substrate incompatibilities or performance degradations across the claimed printing methods and leaf substrate; any leachables or cytotoxicity data, if collected, should be reported to support the biocompatibility claim.
minor comments (2)
  1. [Methods] Figure captions and methods should specify exact printing parameters (viscosity ranges, UV dose, ionic liquid ratio) to enable reproducibility.
  2. [Introduction] The introduction would benefit from a brief comparison table of prior electrolyte formulations versus the new basis with respect to biocompatibility, printability, and stability.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive review and recommendation for minor revision. The comments help clarify the presentation of our stability and biocompatibility claims. We address each point below and have prepared revisions accordingly.

read point-by-point responses

  1. Referee: [Abstract and device characterization] The central stability claim (>30 days ambient operation) is load-bearing for the headline result, yet the abstract and summary provide no quantitative metrics (e.g., transconductance retention, on/off current ratio, or threshold voltage drift) with error bars or replicate counts. Device characterization sections should include time-dependent electrical data with statistical controls to substantiate the lifetime assertion.

    Authors: We agree that quantitative metrics strengthen the abstract. The full manuscript already contains time-dependent electrical data (transconductance, on/off ratios, and threshold voltage over 30 days) with replicate measurements and error bars in the device characterization section. In revision we will add a concise quantitative summary of these metrics (retention percentages, ratio values, and drift) directly into the abstract and ensure the main text explicitly cross-references the statistical controls and time-series plots. revision: yes

  2. Referee: [Materials and methods] The assertion of a 'universal' biocompatible material basis requires explicit validation that the formulation introduces no unstated substrate incompatibilities or performance degradations across the claimed printing methods and leaf substrate; any leachables or cytotoxicity data, if collected, should be reported to support the biocompatibility claim.

    Authors: The term 'universal' denotes the formulation's rheological tunability that enables both inkjet and screen printing plus demonstrated compatibility with the leaf substrate, as shown by successful device fabrication and stable operation without observed degradation. All components are drawn from materials previously validated as biocompatible. We did not perform dedicated leachables or cytotoxicity assays on the final mixture. In revision we will add an explicit paragraph in Materials and Methods that (i) states the absence of new cytotoxicity data, (ii) justifies biocompatibility via component selection with literature references, and (iii) notes the lack of performance degradation or visible incompatibilities across the tested printing methods and leaf substrate. revision: partial

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

This experimental materials development paper contains no derivations, equations, fitted parameters, or predictive models. All central claims rest on direct material selection, printing protocols, rheological measurements, UV-curing behavior, and device characterization data (including >30-day ambient stability and the leaf-substrate transistor demonstration). No self-citations function as load-bearing premises, and no result is presented as an independent prediction that reduces to its own inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Only the abstract is available, so no specific free parameters, axioms, or invented entities can be extracted. The central claim rests on an experimental material formulation whose details and validation are not provided here.

pith-pipeline@v0.9.0 · 5510 in / 1148 out tokens · 131367 ms · 2026-05-07T14:35:11.996517+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

32 extracted references · 32 canonical work pages

  1. [1]

    B. D. Paulsen, K. Tybrandt, E. Stavrinidou, J. Rivnay, Nat. Mater . 2020, 19, 13

    work page 2020

  2. [2]

    T. Li, J. Y. Cheryl Koh, A. Moudgil, H. Cao, X. Wu, S. Chen, K. Hou, A. Surendran, M. Stephen, C. Tang, C. Wang, Q. J. Wang, C. Y. Tay, W. L. Leong, ACS Nano 2022, 16, 12049

    work page 2022

  3. [3]

    Z. Lu, K. Xu, K. Xiao, Q. Xu, L. Wang, P . Li, J. Zhou, D. Zhao, L. Bai, Y. Cheng, W. Huang, Npj Flex. Electron. 2025, 9, 9

    work page 2025

  4. [4]

    A. M. Pappa, D. Ohayon, A. Giovannitti, I. P . Maria, A. Savva, I. Uguz, J. Rivnay, I. McCulloch, R. M. Owens, S. Inal, Sci. Adv. 2018, 4, eaat0911

    work page 2018

  5. [5]

    M. H. Bolin, K. Svennersten, D. Nilsson, A. Sawatdee, E. W. H. Jager , A. Richter- Dahlfors, M. Berggren, Adv. Mater . 2009, 21, 4379

    work page 2009

  6. [6]

    Rivnay, S

    J. Rivnay, S. Inal, A. Salleo, R. M. Owens, M. Berggren, G. G. Malliaras, Nat. Rev. Mater . 2018, 3, 17086

    work page 2018

  7. [7]

    Md. A. B. H. Susan, T. Kaneko, A. Noda, M. Watanabe, J. Am. Chem. Soc. 2005, 127, 4976

    work page 2005

  8. [8]

    X. Fan, S. Liu, Z. Jia, J. J. Koh, J. C. C. Yeo, C.-G. Wang, N. E. Surat’man, X. J. Loh, J. L. Bideau, C. He, Z. Li, T.-P . Loh, Chem. Soc. Rev. 2023, 52, 2497

    work page 2023

  9. [9]

    Zabihipour , R

    M. Zabihipour , R. Lassnig, J. Strandberg, M. Berggren, S. Fabiano, I. Engquist, P . Andersson Ersman, Npj Flex. Electron. 2020, 4, 15

    work page 2020

  10. [10]

    M. I. Baker , S. P . Walsh, Z. Schwartz, B. D. Boyan, J. Biomed. Mater . Res. B Appl. Biomater. 2012, 100B, 1451

    work page 2012

  11. [11]

    W. Hong, M. Meng, J. Xie, D. Gao, M. Xian, S. Wen, S. Huang, C. Kang, J. Adhes. Sci. Technol. 2018, 32, 2180

    work page 2018

  12. [13]

    Rincón-Iglesias, A

    M. Rincón-Iglesias, A. Delgado, N. Peřinka, E. Lizundia, S. Lanceros-Méndez, Carbohydr . Polym. 2020, 233, 115855

    work page 2020

  13. [14]

    Shin, J.-Y

    K.-Y. Shin, J.-Y. Hong, J. Jang, Adv. Mater . 2011, 23, 2113

    work page 2011

  14. [15]

    R. E. Trease, R. L. Dietz, Solid State Technology, 1972

    work page 1972

  15. [16]

    B. Sun, S. F. Wan Muhamad Hatta, N. Soin, M. F. Z. B. A. Kadir , F. A. Md Rezali, S. N. Aidit, L. Y. Ma, Q. Ma, ACS Appl. Electron. Mater . 2024, 6, 2336

    work page 2024

  16. [17]

    L. Lu, X. Liu, P . Gu, Z. Hu, X. Liang, Z. Deng, Z. Sun, X. Zhang, X. Yang, J. Yang, G. Zu, J. Huang, Nat. Commun. 2025, 16, 3831

    work page 2025

  17. [18]

    F. A. S. Leite, P . Wierzchowiec, C. Pinheiro, L. Maggini, D. Bonifazi, Adv. Mater . Technol. 2025, 10, 2401112

    work page 2025

  18. [19]

    F. A. M. Rezali, S. F. Wan Muhamad Hatta, N. Soin, M. H. A.-H. Nouxman, A. S. A. A. Bakar , L.-Y. Ma, B. Sun, IEEE Sens. J. 2026, 26, 7989

    work page 2026

  19. [20]

    D. K. Thukral, S. Dumoga, S. Arora, K. Chuttani, A. K. Mishra, Cancer Nanotechnol. 2014, 5, 3

    work page 2014

  20. [21]

    X. He, B. Zhang, Q. Liu, H. Chen, J. Cheng, B. Jian, H. Yin, H. Li, K. Duan, J. Zhang, Q. Ge, Nat. Commun. 2024, 15, 6431

    work page 2024

  21. [22]

    J. P . Mazzoccoli, D. L. Feke, H. Baskaran, P . N. Pintauro, J. Biomed. Mater. Res. A 2010, 93, 558

    work page 2010

  22. [23]

    Hakim Khalili, V

    M. Hakim Khalili, V. Panchal, A. Dulebo, S. Hawi, R. Zhang, S. Wilson, E. Dossi, S. Goel, S. A. Impey, A. I. Aria, ACS Appl. Polym. Mater. 2023, 5, 3034

    work page 2023

  23. [24]

    Weissbach, L

    A. Weissbach, L. M. Bongartz, M. Cucchi, H. Tseng, K. Leo, H. Kleemann, J. Mater . Chem. C 2022, 10, 2656

    work page 2022

  24. [25]

    R. B. McCleskey, J. Chem. Eng. Data 2011, 56, 317

    work page 2011

  25. [26]

    Solgi, Y

    A. Solgi, Y. Yoon, J. Huang, S. Fabiano, K. Leo, H. Kleemann, Adv. Mater . Technol. 2026, 11, e01582

    work page 2026

  26. [27]

    Khoury, Z

    F. Khoury, Z. Habli, J. Daorah, Y. Xu, M. Obeid, S. Alam, G. Cauwenberghs, M. Khraiche, 2025

    work page 2025

  27. [28]

    U. Boda, I. Petsagkourakis, V. Beni, P . Andersson Ersman, K. Tybrandt, Adv. Mater . Technol. 2023, 8, 2300247

    work page 2023

  28. [29]

    Contat-Rodrigo, C

    L. Contat-Rodrigo, C. Pérez-Fuster , J. V. Lidón-Roger , A. Bonfiglio, E. García-Breijo, Sensors 2016, 16, 1599

    work page 2016

  29. [30]

    L. M. Bongartz, R. Kantelberg, T. Meier , R. Hoffmann, C. Matthus, A. Weissbach, M. Cucchi, H. Kleemann, K. Leo, Nat. Commun. 2024, 15, 6819

    work page 2024

  30. [31]

    J. Li, D. Mo, J. Hu, S. Wang, J. Gong, Y. Huang, Z. Li, Z. Yuan, M. Xu, Microsyst. Nanoeng. 2025, 11, 87

    work page 2025

  31. [32]

    M. Yang, Y. Zhang, H. Zhang, Z. Li, in 10th IEEE Int. Conf. NanoMicro Eng. Mol. Syst., 2015, pp. 149–151

    work page 2015

  32. [33]

    R. R. Nair , J. Wolansky, K. Uhlig, A. Solgi, L. Teuerle, T. Zhang, J. Schröder , T. Antrack, J. Benduhn, H. Kleemann, K. Leo, Sci. Adv. 2024, 10, eadq3276. Supplementary Material Figure S1: SEM micrograph of a layer of screen printed IGI with a screen of 36 threads / cm. For better visibility of the topography, the sample was imaged at a tilt angle of 30...

    work page 2024