Collaborative Research: "Green" Nanolithography Using Protein-based Photoresists

在传统的纳米制造中，迫切需要减少在光刻过程中作为光刻胶和显影剂的有毒化学物质的使用。该合作研究奖解决了纳米制造中的这一根本问题，使用生物兼容蛋白质作为光致抗蚀剂，消除了微/纳米光刻过程中对危险化学品的需求，并降低了相关的安全成本。这也将有助于理解生物聚合物蛋白质与入射辐射相互作用的基本机制，即蛋白质受光照射后的变化。基于蛋白质的生物聚合物的物理和化学性质方面的知识有望广泛应用于蛋白质光子、蛋白质电子和蛋白质离子光刻工艺，为下一代绿色纳米制造铺平道路。这两个机构之间的合作分别结合了它们在纳米制造和纳米表征方面的优势，并为不同的本科生和研究生群体提供了独特的教育机会。这包括教育活动，包括制定课程、招收和保留代表人数不足的学生，以及与学校进行接触。合作研究成果将通过技术出版物、会议和研讨会、定期和短期课程广泛传播。一系列基于蛋白质的生物聚合物-包括再生的天然蛋白质和重组蛋白质-将以薄膜形式进行分析，以评估它们作为仅以水为显影溶剂的纳米光刻抗蚀剂材料的适用性。将利用扫描电子显微镜和扫描近场光学显微镜在纳米尺度上对这些生物聚合物的物理和化学性质进行全面的研究，以评估它们在不同光刻条件下的抗蚀性能。还将研究以蛋白质为基础的生物聚合物作为大规模纳米制造(例如卷到卷纳米印迹)的抗蚀剂和模板材料的用途。这项研究还将提供一种新的、具有成本效益和生态友好的方法，不仅用于图案转移，还用于制造可用作生物界面的纳米结构，其分辨率与传统光刻方法相同或更高。这项研究，当实施高分辨率表征和光刻程序时，将发现许多应用，包括但不限于用于组织工程的生物传感器、生物光子学和生物结构，因为与合成同行相比，生物相容性固有的更好。

There is an urgent need to reduce the use of noxious chemicals as photoresists and developing solvents during lithographic processes in conventional nanofabrication. This collaborative research award addresses this fundamental issue in nano-manufacturing by using bio-compatible protein as the photoresist, eliminating the need of hazardous chemicals during micro/nano-lithography and reducing the associated safety costs. It will also facilitate the understanding of the fundamental mechanism of the interaction between biopolymer proteins and incident radiation, that is, changes in proteins upon exposure to light. The knowledge obtained of the physical and chemical properties of protein-based biopolymers is expected to be widely applicable to protein-photon, protein-electron and protein-ion lithography processes, paving the way for the next generation "green" nanomanufacturing. The collaboration between the two institutions combines their strengths in nano-fabrication and nano-characterization, respectively, and provides unique educational opportunities to a diverse group of undergraduate and graduate students. This includes educational activities comprising curriculum development, recruitment and retention of under-represented students, and outreach to schools. The collaborative research results will be broadly disseminated through technical publications, conferences and workshops, regular and short courses.A set of protein-based biopolymers - including regenerated natural and recombinant proteins - will be analyzed in thin-film form to evaluate their suitability as the resist materials for nanolithography with only water as the developing solvent. Comprehensive studies of the physical and chemical properties of these biopolymers will be conducted at the nanoscale using scanning electron microscopy and scanning near-field optical microscopy to assess their resist performance under different lithographic conditions. The uses of protein-based biopolymers as resist and template materials for large-scale nanomanufacturing (e.g. roll-to-roll nanoimprinting) will be investigated as well. The research will also provide a new, cost-effective and eco-friendly methodology not only for pattern transferring but also for fabricating nanostructures that can serve as biointerfaces with the same or better resolution than conventional lithographic methods. This research, when implemented with high resolution characterization and lithography procedures, will find numerous applications including but not limited to biosensors, biophotonics, and biostructures for tissue engineering owing to the inherently superior biocompatibility compared to synthetic counterparts.