The mixed transport of electrons and ions in polymeric systems is inspired by living systems and therefore of particular importance for bioelectronics [1]. Conducting scaffolds composed of conducting polymers can enhance interactions with cells for biosensing and stimulation, thus also resembling processes occurring in nature [2,3]. The conducting material in these scaffolds can be the base material itself or an additive that infers conducting properties to an insulator [4].

We employ 2-photon lithography to generate (semi-)interpenetrated hydrogel network structures with sub-micron resolution. Conductivity is achieved through implementation of in-house synthesized conducting polymers, such as Poly(3,4-ethylenedioxythiophene) (PEDOT-S), and ionically active monomers, into 2-photon printable hydrogel inks. One example of these hydrogel are Gelatin-based formulations that have cell native character. To validate our material, the formation of the conductive double network is characterized using conductivity measurements, electrochemical impedance spectroscopy (EIS), FTIR analysis, and light microscopy.

By tailoring conductive 3D hydrogel scaffolds, we will be able to optimize the way we interface with single cells, cell populations, or tissues. The generation of (semi-)interpenetrating networks of organic polymers with mixed conductance behaviour within 3D structured hydrogels provides a first step towards enhancing interaction and mimicking living systems.  

 [1] S. Hazra, A. Banerjee, A. K. Nandi. ACS Omega, 2022, 7(37), 32849-32862.
[2] J. Hungenberg, A. Hochgesang, F. Meichsner, M. Thelakkat Advanced Functional Materials, 2024, 34, 2407067.
[3] C. Arndt, M. Hauck, I. Wacker, B. Zeller-Plumhoff, F. Rasch, M. Taale, A. Nia, X. Feng, R. Adelung, R. Schröder, F. Schütt, C. Selhuber-Unkel. Nano Letters, 2021, 21(8), 3690-3697.
[4] A. Mousa, D. Bliman, L. Betancourt, K. Hellman, P. Ekström, M. Savvakis, X. Strakosas, G. Marko-Varga, M. Berggren, M. Hjort, F. Ek, R. Olsson. Chemistry of Materials. 2022, 34(6), 2752-2763.