Table 1 Physical properties and performance of V-SPA Module.

Performance metrics were estimated from an angular displacement step response test recorded relative to gravity using an IMU fixed to the upper stage of the module and with 86.2% vacuum supply.

PropertiesValueUnit
Size (D × H)45 × 45(mm)
Total module weight45.0(g)
  V-SPAs (×3)11.1(g)
  Solenoid valves (×3)12.0(g)
  PCBs8.5(g)
  Acrylic and epoxy
layers
8.5(g)
  Central conduit
(tubes, connectors,
wires)
4.9(g)
Blocked torque166.9(N∙mm)
Specific torque
(relative to actuator
mass)
45.1(N∙mm/g)
Angular velocity, ω (no
load)
3.5(°/s)
Step rise time, tr1.5(s)
Step decay time, td2.4(s)
Bandwidth0.2(Hz)
Maximum angular
stroke, α (no load)
27.3(°)
Specific power (relative
to actuator mass)
5.0(W/kg)
Specific energy
(relative to actuator
mass)
1.2(J/kg)