Lucherini Lorenzo, Navello Veronica, Akouissi Outman, Lacour Stéphanie P, Amstad Esther
Soft Materials Laboratory, Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Laboratory for Soft Bioelectronic Interfaces, Neuro X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland.
Mater Today Bio. 2025 Jul 30;34:102140. doi: 10.1016/j.mtbio.2025.102140. eCollection 2025 Oct.
Hydrogels have emerged as promising materials for bioelectronic interfaces due to their tissue-like properties and high-water content. However, conventional hydrogels often suffer from poor electrical conductivity and mechanical stability, limiting their performance in long-term bioelectronic applications. Electronic conductivity can be imparted to hydrogels by functionalizing them with conductive particles. However, patterning of electronically conductive features within hydrogels remains challenging. Electronically conductive μm-sized patterns embedded in soft hydrogels would open up new possibilities to integrate hydrogel bioelectronics with electronic devices. Here, we introduce covalently crosslinked hydrogels with Young's moduli below 30 kPa that can be functionalized with metallic electronically conductive paths reaching an electronic conductivity up to (1505 ± 518) S cm. By tailoring the hydrogel substrate composition, we achieve writing fidelity up to ±5 %, with feature width as narrow as 5 μm. Using two-photon direct laser writing, we demonstrate the ability to pattern encapsulated conductive structures at the surface or within the bulk of the hydrogels. These patterned hydrogels offer new opportunities for creating soft, miniaturized bioelectronic interfaces, with potential applications in cellular and tissue electrophysiology.
由于水凝胶具有类似组织的特性和高含水量，它们已成为生物电子界面领域颇具前景的材料。然而，传统水凝胶通常存在导电性差和机械稳定性不佳的问题，这限制了它们在长期生物电子应用中的性能表现。通过用导电颗粒对水凝胶进行功能化处理，可以赋予其电子导电性。然而，在水凝胶内部形成具有电子导电性的图案仍然具有挑战性。嵌入柔软水凝胶中的微米级电子导电图案将为水凝胶生物电子学与电子设备的集成开辟新的可能性。在此，我们介绍了杨氏模量低于30 kPa的共价交联水凝胶，这种水凝胶可以通过金属电子导电路径进行功能化处理，其电子电导率高达(1505±518) S/cm。通过调整水凝胶基质的组成，我们实现了高达±5%的写入保真度，特征宽度窄至5μm。利用双光子直接激光写入技术，我们展示了在水凝胶表面或内部对封装的导电结构进行图案化的能力。这些图案化水凝胶为创建柔软、小型化的生物电子界面提供了新的机会，在细胞和组织电生理学方面具有潜在应用价值。
