Experimental setup. (a) Actuation unit with, from left to right, capillary tubes through which the Nitinol wires are fed, telescopic sliders connected to universal joints, linear stepper motors, and optical sensors (drawing in SolidWorks 2018 by Menno Lageweg/CC by 4.0). (b) Section view of the frontal part of the actuation unit showing the clamping point of the wire and the telescopic system serving as a buckling prevention mechanism for the wire (drawing in SolidWorks 2018 by Menno Lageweg/CC by 4.0). (c) Telescopic tube system consisted of three capillary tubes (T1, T2, and T3). (d) Photo of the experimental setup used during the needle insertion experiments.