“…[214][215][216] So far, while much of this manuscript had revolved around the use of solid-state materials to produce SAW devices, it is important to note that another interesting trend in the development of SAW devices in recent years had been the utilization of flexible material such as polymers for the development of more versatile, reusable, and biocompatible SAW biosensors. Despite the fact that most work on flexible SAW sensing devices have so far focused on the detection of factors such as pressure, temperature, and humidity, [217][218][219][220][221][222][223][224] some studies have also been reported on SAW biosensors using piezoelectric thin film such as AlN and ZnO deposition on different polymer substr ates. [13,60,134,219,225,226] The use of piezoelectric thin film material permits for the deposition and the localization of the film solely on the SAW propagation region through micromachining [227] and also makes it possible to incorporate various functions such as wearability and tactility.…”