Singh Seminar Series: Yuh-Shiuan Chien and Jamie Ford

From 2D to 3D: Developing High-Sensitivity and Automated Stacking-Based Paper Biosensors

Speaker: Yuh-Shiuan Chien

Abstract: Conventional paper-based sensors have achieved widespread adoption in fields such as pregnancy testing and COVID-19 rapid screening, leveraging their low cost, ease of operation, and high commercial viability. However, constrained by a two-dimensional physical framework and a single capillary flow path, traditional designs often face bottlenecks including insufficient sensitivity, significant sample loss, and limited functionality, making them difficult to apply in complex biological sample analysis.
To address these challenges, we leverage the structural ingenuity of origami and stacking to create three-dimensional flow channels within a highly confined physical space. This spatial evolution provides an ideal platform for integrating signal amplification techniques, such as bimetallic deposition, which significantly lowers the limit of detection. Simultaneously, by precisely defining hydrophobic and hydrophilic boundaries through wax printing, we establish an automated fluidic navigation system in the microcosmos. This design enables solutions to flow autonomously according to a precise temporal sequence, allowing complex reactions to be completed sequentially on a single test strip. This technological progression allows paper-based sensors to overcome the sensitivity and operational constraints of traditional tools, transforming them into high-stability, point-of-care diagnostic devices capable of meeting diverse clinical needs.

About the Speaker: Yuh-Shiuan Chien is a postdoctoral researcher at the Institute of Applied Mechanics, National Taiwan University, and a visiting scholar in Mechanical Engineering and Applied Mechanics at the University of Pennsylvania. His research lies at the interface of microfluidics, biosensing, nanomaterials, and point-of-care diagnostics. His work spans paper-based analytical devices, lateral and vertical flow immunoassays, microfluidic chips, and portable diagnostic systems for blood analysis and disease detection.

The Wonderful World of Helium Ion Microscopy

Speaker: Jamie Ford

Abstract: The Zeiss Orion Helium Ion Microscope (HIM) is a powerful direct-write nanopatterning and high resolution imaging platform. This talk will introduce the newest addition to the Nanoscale Characterization Facility, its capabilities, and how it fits into the array of microscopy and patterning techniques available at the Singh Center for Nanotechnology.

About the Speaker: Jamie Ford received a BA in Chemistry from Reed College in 2002 and a PhD in Materials Science and Engineering from the University of Pennsylvania in 2009. His main duties include instrument maintenance and user training for the Scanning Electron and Ion Microscopes in the NCF. He is an expert in spending other people's money on novel instrumentation for the Singh Center.

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