Micropatterning of Mussel-Inspired Materials to Empower Selective Functionality of Microdevices

Universal surface modification platforms are crucial for enhancing the functionality of novel materials and microdevices. Mussel-inspired materials (MIMs) show great potential due to their strong adhesive properties and versatile post-functionalization capabilities. However, traditional MIM coating methods suffer from poor deposition selectivity and a lack of structural control. To address these limitations, we have developed an innovative micropatterning technique for MIMs using multiphoton lithography (MPL).
This novel method eliminates the need for photomasks, stamps, or multistep processes, allowing the creation of patterns with submicrometer resolution and full design freedom. We successfully applied MPL to create intricate 2D and 3D structures using various MIMs, including polydopamine (PDA) and linear and dendritic mussel-inspired polyglycerols (MI-lPG and MI-dPG) [¹,²]. The achieved resolution of patterns was 250 ± 20 nm for MI-dPG and 800 ± 100 µm for PDA.
One of the key advantages of this technique is its flexibility. The topography of patterns, resolution, and throughput of MIM micropatterning can be readily adjusted by modifying laser power, scanning speed, and solution formulation. This adaptability allows for the creation of a wide range of morphologies, from the grain-like structure inherent to PDA to the continuous smooth morphology of MI-PG.
To demonstrate the multifunctional capabilities of the micropatterned MIMs, we explored several applications. First, we showcased their potential for targeted DNA sensing by successfully functionalizing MIM micropatterns with DNA probes and subsequently hybridizing fluorescent, sequence-specific single-stranded DNA fragments. This application highlights the potential use of MIM micropatterns in biosensing and molecular diagnostics. We also performed facile posts-modification of the PDA surface with protein enzymes like trypsin that was confirmed by XPS. Obtained bioactive pattern could be further integrated in the protein sensing devices.
Additionally, we demonstrated the ability to perform one-step facile silver (Ag) immobilization on MIM micropatterns. This process resulted in high metal particle coverage and can be applied for electroless metallization in complex microdevices. The successful metallization of MIM micropatterns opens up possibilities for applications in microelectronics and conductive microstructures.
When comparing the different MIM types, we found that the dendritic polyglycerol derivative exhibited superior performance in terms of pattern quality, fabrication throughput, and post-immobilization capability. This finding provides valuable insights for selecting the most suitable MIM for specific applications.
The development of this MPL-based micropatterning technique for MIMs represents a significant advancement in the field of surface modification and microdevice fabrication.The ability to precisely control the deposition and structure of MIMs at the microscale, coupled with their inherent adhesive properties and post-functionalization capabilities, paves the way for the development of next-generation materials and devices with enhanced performance and functionality.
1. Tavasolyzadeh, Z. et al. 2D and 3D Micropatterning of Mussel-Inspired Functional Materials by Direct Laser Writing. Small 20, 2309394 (2024).
2. Topolniak, I. et al. High precision micropatterning of polydopamine by Multiphoton Lithography. Adv. Mater. 2109509 (2022) doi:10.1002/adma.202109509.