Elliptical-like cross-section ionic polymer-metal composite actuator for catheter surgery

Catheter surgery is one of the surgical methods for brain, vessel, and heart surgery in which doctors insert medical tools through the vessels using catheter tubes. However, as it is performed by human hand, operating upon miniscule vessels, for example, deep within the brain, is difficult. Hence, robot catheter systems that can move the tip of the catheter are desired. Herein, we present a novel method for controlling the catheter system and a new ionic polymer-metal composite (IPMC) catheter design. The optimum value of the second moment of area is 0.18 × 10−3 mm4, which is only 0.63% of that of a true-circle tube. However, using this design, a catheter with a 0.46 × 10−2 mm4 second moment of area, which is 16% of that of a true circle tube, is fabricated. In the experiments, the tip of the catheter moves by 1.67 mm and the 25 mm length point from the root by 0.90 mm for applied voltages of 2 V, respectively. The proposed value is 2 mm (±1 mm), which is greater by a factor of 2.2 than the obtained experimental result. However, by simulated calculation, the second moment of area can be reduced by a factor of 25.