M.Sc Thesis

M.Sc StudentBachar Nadav
SubjectDecoupling between Various Stimuli in Multiparametric Gold
Nanoparticles based Flexible Sensors
DepartmentDepartment of Chemical Engineering
Supervisor PROF. Hossam Haick
Full Thesis textFull thesis text - English Version


Flexible sensors could soon replace conventional, rigid sensors in existing applications and spur the development of totally new smart sensing applications, including, but not confined to consumer electronics, robotics, prosthetics, health care, geriatric care, sports and fitness, safety equipment, environmental monitoring, homeland security and space flight. For many applications that involve new generations of integrated circuits ? such as electronic skin (a device that mimics human skin)?temperature, humidity and strain sensors on flexible substrates are urgently needed. In this work, we present temperature, humidity and touch (or strain) flexible sensors based on monolayer-capped gold nanoparticles(Au-MCNPs) films that are potentially inexpensive, could allow low voltage operation and provide a platform for multifunctional applications. We show that modifying the Au-MCNPs nanostructural parameters (ligand length and particle size) enables controlling and tuning their electrical and sensing properties. In general, we show that larger particles and longer ligands yield higher response sensitivities to the different stimuli discussed and that all sensors exhibited repeatable responses. In addition, choosing the appropriate nanostructural parameters acts as a powerful tool for governing the cross-reactivity of the Au-MCNP sensor. Furthermore, we demonstrate the feasibility of modeling the sensor response and the interaction effects between the different stimuli. Ultimately, we were able to build an Au-MCNP based flexible prototype allowing simultaneous detection and monitoring of multiple environmental parameters of temperature and mechanical strain (convex and concave bending). We show that this modified platform allows wide ranging and precise detection of mechanical force or elastic deformation. The excellent mechanical strain sensitivities (detection limit and resolution of ~10 gF) and temperature (resolution higher than 1%oC-1) and the possibility to integrate these sensing abilities makes the suggested platform interesting for potentially inexpensive and low voltage multifunctional electronic-skin applications.