Novel Spontaneous Freeform PMMA Thin-Film Development and Quantification
ORAL
Abstract
Thin films are foundational to multiple applications, including microelectronics, photonics, and biomedical devices. As demand for large-area thin films grows, traditional methods—spincasting and vacuum deposition—face increasing limitations due to material waste, scalability, and substrate compatibility. These techniques often require expensive equipment or are constrained by substrate geometries. Resource-efficent or large-area thin film fabrication methods would greatly benefit academia and industry.
In this work, we characterize freeform formation of poly-methyl methyacrylate(PMMA) thin films independent of specialized equipment. We describe several variant freeform development setups and PMMA thin film behavior. The approach harnesses Marangoni flow, covering similar surface area at a fraction that spincasting needs. Increasing the temperature over the range 25°C to 50°C of the solution and surface did not significantly impact on surface area. Film thickness averaged 2336 Å with standard deviation 28 Å. Coated wafers were patterned using a quartz/Cr photomask and UV light 365nm (intensity 10mW/cm2) for 16 hours, yielding well-defined wells. Applying spontaneous thin films to ordered DNA fragmentation yielded DNA deposition and successful selective DNA cutting with Tn5 Transposase. As conventional spincasting requires ~250 μL solution for equivalent area, this novel development method demonstrates potential to reduce thin film resource costs by up to 83x.
In this work, we characterize freeform formation of poly-methyl methyacrylate(PMMA) thin films independent of specialized equipment. We describe several variant freeform development setups and PMMA thin film behavior. The approach harnesses Marangoni flow, covering similar surface area at a fraction that spincasting needs. Increasing the temperature over the range 25°C to 50°C of the solution and surface did not significantly impact on surface area. Film thickness averaged 2336 Å with standard deviation 28 Å. Coated wafers were patterned using a quartz/Cr photomask and UV light 365nm (intensity 10mW/cm2) for 16 hours, yielding well-defined wells. Applying spontaneous thin films to ordered DNA fragmentation yielded DNA deposition and successful selective DNA cutting with Tn5 Transposase. As conventional spincasting requires ~250 μL solution for equivalent area, this novel development method demonstrates potential to reduce thin film resource costs by up to 83x.
*The authors would like to thank the Garcia Research Scholar's Program for sponsoring the facilities, mentorship, and associated costs with the research conducted.
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Presenters
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Selina Zhang
- Harvard University