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

•We proposed novel IPMC catheter design for surgery.•It has track-shaped cross-section which has lower second moment of area than true-circle tube.•We measured the displacement of IPMC catheter by camera measurement system.•The tip of the catheter moved by 1.67mm for applied voltages of 2V. 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 0.18×10−3mm4, which is only 0.63% of that of a true-circle tube. However, using this design, a catheter with a 0.46×10−2mm4 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 1.67mm and the 25mm length point from the root by 0.90mm for applied voltages of 2V, respectively. The proposed value is 2mm (±1mm), 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.