The following steps describe our methodology for preparing soft actuators.
Coating the molds in Vaseline would later help removing the cured silicone from the mold.
Refer to the silicones page to figure out the ratio working time of your silicone. If you don't have a centrifugal mixer, use wooden mixing sticks. Mix thoroughly for 3 minutes. Weak mixing may result in curing failure.
5 minuets should be enough to get rid of initial bubbles.
Pour gently and slowly. Allow the silicone to spread evenly and then pour more layers. For the base layer, pour only half of the silicone, as you will later add the strain limiting layer.
After 5 minutes lots of bubbles will rise to the surface. Pop them out with a pipette tip or other plastic instrument.
Refer to the strain limiting page for more info.
Each mold may have different methods for removing. The silicone is quite strong so it's OK to use a flathead screwdiver. We have also used a metal knitting needle to cut through the seams of the mold.
Notice that if you overfilled your mold, you may have silicone attached above the edges of the mold. Use a utility knife to cut the excess attachment.
Do not reuse old silicone as it may have already been cured.
Refer to the soft robotics toolkit guide:
Place the top piece of the actuator on the base so that it settles into the uncured Silicone, and press down gently. If you press too hard, the central channel of the actuator may become blocked. Make sure to press down around the edges as well to ensure a good seal.
Use the metal knitting needle to pierce the hole and gently attach the tube. Refer to the page of your mold for specific instructions on where and how to pierce the hole.
Do not inflate too much! - If the inflation works properly, let the actuator rest and cure until the next day. Two main issues may be revealed: