Hasel Muscle

Hasel muscle is used in soft-robotics for movement of robot elements.
Supplies
cord
string bags
glycerine
nail polish or glue
coal dust
high voltage power supply
Preparation of String Bags

Cut a small square at the bottom of the string bag.
Fill String Bag

Fill the uncut string bag with glycerine to half its volume.
Tie the Cord

Tie and then thread the string through the square cut at the beginning.
Pack String Bag Inside String Bag

Pack one string bag into another to fill the free space exactly.
Thread the String Through

Thread one string through the slot of the string bag so that one string is next to where the other string is tied.
Position of the Electrodes

Glue carbon dust from both sides of the bag onto glue or nail polish.
Finish

The last stage is to apply a high voltage to the electrodes, the pressure will be exerted under the influence of attracting electrodes on the bag, then it will stretch by pulling the string.