Figure 2. Mechanical characteristics of the paraffin wax trigger and fold angle optimization of the single cell grippers.
(a) Stress/strain curve for paraffin wax at temperatures of 26°C and 37°C based on DMA measurement. Inset shows the initial linear range. (b) Analytical study of the fold angle of single cell grippers as a function of paraffin thickness at 26°C and 37°C, based on the analytical solution from reference.32 (c) Finite element simulation snapshots of single cell grippers with two different wax thicknesses at 26°C and 37°C. (d) Folding process of single cell grippers before release, after release, and during the heating process from room temperature to 37°C. The gripper in the left column did not have paraffin layer; the three grippers in the right column had paraffin layer on top as indicated by the dark edge and coating all over the gripper in the first row.