Development of a microsensor device for surgical robots to measure the force to detach tumors

Micro-force sensors are of utmost importance for a variety of state-of-the-art biomedical devices that require micro-manipulative operations with high precision and accuracy. Unfortunately, the measurement accuracy of miniaturized sensors decreases as they become smaller. Conventional sensing systems such as piezoelectric sensors are also inadequate for numerous sensing applications because they exhibit a decrease in detection output when scaled down. In contrast, a micro-force sensor equipped with a hydraulic drive mechanism can obtain a large output even when the size is significantly reduced. By observing the pressure change in the water feeder, the external force applied to the end effector can be measured. In this study, we measure the mechanical properties of cancer tumors, which are a leading cause of death, by using a peeling motion, as cancer tumors tend to be harder than benign tumors and the tensile reaction force increases as the neovascularization of the tumor expands. First, a simulated tumor model was created to measure the change in reaction force with hardness, and viscoelasticity was then measured and evaluated by a peeling motion using a hydraulic drive mechanism.