An Optical Reporting Patch for Spatiotemporal Measurements of Water Activity in Complex Environments
Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Water activity, a w, is an important state parameter in a wide variety of natural and technological contexts. Existing tools to measure water activity in situ and with spatial and temporal resolutions are limited. Here, we present the development of a composite silicone patch, AquaSheet, that reports water activity as a fluorescence signal. We proceed to demonstrate two modes of measurements: (i) spatially averaged, temporally resolved measurements with a commercial reflectance probe and spectrometer that is appropriate for measurements in both gases and liquids and (ii) spatially and temporally resolved measurements with a custom-built imaging system that allows for tracking the spatiotemporal evolution of a soil drying process. We conclude with a discussion of additional applications, limitations, and opportunities for improvement of the AquaSheet technology.
Source: Analytical Chemistry
Authors: I-Feng Wu, Piyush Jain, Sahil A. Desai, Vesna Bacheva, Sabyasachi Sen, Annika E. Huber, Abraham D. Stroock
Institution: Cornell University
Language: English
Subfield: Bioengineering
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1523888516, STC: Center for Research On Programmable Plant Systems, G3770527471, G3875989753, SitS NSF- Field deployable sensing of the plant-soil interface: innovative bio-mimetic robots to understand dynamic soil processes and accelerate root and rhizosphere productivity, NSF-ANR MCB/PHY: Elucidating Plant Vascular Function and Dynamics in Planta and on Chip, G6386519147, NNCI: Cornell NanoScale Science and Technology Facility (CNF)
OpenAlex ID: W7154332819