This thesis is structured into five main chapters, as well as the introduction, literature review, and conclusions. As previously mentioned, this thesis is divided into two distinct fields, and is linked by the 3ω method. To clarify, a pictorial representation of the thesis structure is shown in Figure 1.1. The first chapter discusses the 3ω method and the steps that were taken to establish the technique at the University of Canterbury, New Zealand. The second chapter applies the “classical” 3ω method to a composite pressed nanoparticle material. Three different blends of nanoparticle materials were measured and compared to literature values for similar systems. The third chapter discusses a highly structured nanoparticle- polymer superlattice. The thermal conductivity of this thin film is investigated using the differential 3ω method, and compared to the raw constituent materials. The fourth chapter adapts the 3ω method for use in a microfluidic channel and uses it to measure fluid velocity with spatial resolution. The fifth chapter uses the microfluidic device to assess the growth of a species of oomycete, a type of water moulds related to species currently causing widespread damage to New Zealand’s ecosystem.