DECEMBER 2020 * IEEE ROBOTICS & AUTOMATION MAGAZINE * 61 Bending Angle (°) 10 9.5 9 8.5 8 7.5 7 6.5 6 5.5 5 70 75 80 85 90 0 0 100 150 200 250 Number of Sample (a) 300 350 400 50 100 19 20 21 22 23 24 25 300 350 400 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 35 40 45 50 55 60 65 50 100 150 200 250 Number of Sample (b) 50 100 300 350 400 50 100 150 200 250 Number of Sample (d) 150 200 250 Number of Sample (e) 300 350 400 300 350 400 Iteration 1 Iteration 2 Iteration 3 Iteration 4 Iteration 5 Iteration 6 Iteration 7 Iteration 8 0 0 Iteration 1 Iteration 2 Iteration 3 Iteration 4 Iteration 5 Iteration 6 Iteration 7 Iteration 8 Iteration 1 Iteration 2 Iteration 3 Iteration 4 Iteration 5 Iteration 6 Iteration 7 Iteration 8 0 150 200 250 Number of Sample (c) Iteration 1 Iteration 2 Iteration 3 Iteration 4 Iteration 5 Iteration 6 Iteration 7 Iteration 8 50 Iteration 1 Iteration 2 Iteration 3 Iteration 4 Iteration 5 Iteration 6 Iteration 7 Iteration 8 Figure 7. (a)-(e) Optimization of the proposed soft finger: convergence of the design parameters to the final optimized values (the blue lines show the moving average of each design parameter). The (a) bending angle, (b) joint length, (c) chamber diameter, (d) chamber-to-wall thickness, and (d) joint diameter. Chamber Diameter (mm) 95 Joint Diameter (mm) Joint Length (mm) Chamber-to-Wall Thickness (mm)