Superhydrophobic electronic tongue

• Grant number: 25/15950-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Antonio Riul Júnior
• Grantee: Amanda dos Santos Perillo
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 24/00998-6 - Center for Research and Innovation on Smart and Quantum Materials (CRISQuaM), AP.CEPID

Abstract

We might think, in principle, that chemical composition and surface energy are predominant factors in controlling the wettability of surfaces, but the hierarchy of roughness in micro/nanostructures is the primary factor in controlling hydrophilicity and hydrophobicity. In this sense, mimicking nature is a sensible strategy due to the diversity of examples in incorporating functionalities into different sensing. Here, we will explore changes in the architecture of nanostructured that lead to this hierarchy of roughness. The thin films will be fabricated using the layer-by-layer (LbL) assembly assembly, deposited on interdigitated electrodes (IDEs). The IDEs are in a geometry that provides micrometric roughness, and the LbL films follow this profile. To control roughness at the nanoscale, we will deposit metallic nanoparticles of varying sizes as the outermost layer in the LbL structures that we will use as sensing units in a microfluidic electronic tongue. The aim here is to induce an increase in the contact angle at the IDEs and alternatively, if necessary, we intend to check the deposition via sputtering of a thin fluorine layer on the nanoparticle layer to increase hydrophobicity. This wettability control hinders contaminants from adhering to the detection regions, reducing the need for intermittent cleansing and the possibility of cross-contamination. We will also check how these coatings affect the sensitivity and reliability of the impedance measurements we carry out over a wide frequency range. The proposal is unprecedented, as to date, there are no e-tongues exploring this wettability control at the sensing units. In this way, the proposed developments will contribute to more accurate and faster diagnoses in this analysis as we would avoid intermittent washing in independent measurements and the possibility of cross-contamination, expanding the use of these devices in continuously monitoring various processes. (AU)