List of Symbols
Symbol	Explanation
$A$	Cross-sectional area of pneumatic actuator
$a, b, c$	Fractional section lengths (a, b, c $\in \mathrm{R} \left(0, 1\right) \mathrm{and} a+b+c<1)$
$d_{ei}$	Distance between the neutral axis and the void center
$E$	Young’s modulus
$F$	Tensile force
$I_i$	Second moment of area
$L_i$	Length of each section
$L_{top,i},L_{bot,i}$	Length of top & bottom side
$L_{tot}$	Total length of PDMS microtube
$M_i$	Bending moment of each section
$p$	Pneumatic pressure
$p_o$	Current applied pneumatic pressure
$p_{max}$	Maximum applied pneumatic pressure
$r_{in}$	Cylindrical template radius
$s$	The original axial coordinate of the undeformed pneumatic actuator
$t_{ti}$	Top wall thickness of each segment
$t_{bi}$	Bottom wall thickness of each segment
$\phi$	Deviation angle
$x\left(s\right), y\left(s\right)$	x, y-axis deformed coordinate
$x_i, y_i$	x, y coordinate (in line-segment model)
$\epsilon$	Engineering strain
${\epsilon }_{top,i}, {\epsilon }_{bot,i}$	Top and bottom wall strain
$\sigma$	Engineering stress
${\theta }_i$	Final tilt angle (in line-segment model)