A Resonant Vibrating Tactile Probe for Biomedical Applications Based on IPMC

In the paper, a vibrating tactile probe is presented. The probe exploits the dependence of its resonant frequency on the varying load and hence on the contacted material. This methodology allows the recognition of different materials by observing the electrical quantities involved in the probe dynamics. More specifically, two ionic polymer-metal composite (IPMC) strips are used, one as actuator and one as sensor, that work together for the recognition of materials. The actuator forces the system into resonant conditions that, as stated before, change with the mechanical properties of the contacted material. The output signal produced by the IPMC sensor contains the information required for the estimation of the contacting material. The sensing capabilities could be exploited in various biomedical applications, such as catheterism and surgical resection of tumors. The model and the experimental validation of the proposed probe are reported. For each material, different surveys were collected to estimate the uncertainty of the resonant frequency and hence to obtain the characteristic diagram of the device along with its uncertainty. The reported results show that the developed probe can be used to distinguish among different materials.