A Low-Cost, Disposable, and Contactless Resonant Mass Sensor

Low-cost and disposable sensors are becoming strategic for several applications particularly when devices must operate in hostile environments involving contaminants or irreversible processes. The device presented in this paper is a low-cost contactless mass sensor realized by a rapid prototyping technique. The sensor can be suitable for chemical and biomedical applications due to the disposable nature of the sensing element. The latter is a flexible cantilever beam partially covered by a paramagnetic nanoparticle layer and driven into an oscillating regime by a magnetic actuation. The beam deflection, which is strictly correlated to the target mass, is estimated by a remote inductive readout strategy. The device architecture is presented along with models and simulations allowing the prediction of its sensing features. Moreover, the real behavior of the device is discussed through experimental results confirming the suitability of the proposed sensing strategy.