Granular Jamming Membranes

With this steps you can fabricate custom membranes, in particular the granular jamming membranes to be inserted in the central channels of the modules.    

1. Fabrication of the granular jamming membranes

The membranes fabrication is based on Latex material because it ensures good performance when the vacuum is applied. However, you can choose to fabricate the membranes with another material, for example the Ecoflex 0050 Silicone, if you do not need a strong vacuum level. 

1.1 Pour 5 g of liquid latex into a mixing cup.
1.2 Dip the mold (cylinder for the membrane) inside the liquid latex until the surface is completely covered (a).
1.3 Put the dipped mold in a support (a plastic piece with a hole) and let it dry under a hood for 20 min (b).
1.4 Repeat the dipping phase again. 

1.5 Remove the membrane from the mold (c). 

Remember to fabricate 3 membranes, one for each module of the manipulator (Membrane 1, 2, 3).

Membrane fabrication

2. In-series connection of three granular jamming membranes

2.1 Cut two plastic tubes to 12 mm length and one tube to a longer desired length (300 mm for example).

2.2 Cut three squared pieces of about 100 mm2 of nylon tissue. Close both the ends of the short tubes with this tissue using Parafilm or superglue, then close only one end of the longer tube.

2.3 Fill the Membrane 3 (that is the membrane of the Module 3) with 4 g of powder coffee, insert one short tube (the end with the filter) inside the filled membrane and fix it around the tube using Parafilm.

2.4 Insert the other end of the same short tube inside Membrane 2 holding its top side directly with the tube and fix it around the tube using Parafilm. Fill Membrane 2 with 4 g of powder coffee.

2.5 Repeat 2.4 for connecting Membrane 2 to Membrane 1.

In-series membranes

3. Insertion of granular jamming membranes into the manipulator

3.1 Apply the vacuum with the vacuum pump on the freeside of the long tube (the membranes become stiffer).

3.2 Insert Membrane 3 inside the empty central channel of Module 3. Slide Module 2 up to Membrane 2 passing the long tube through the central channel. Repeat for Module 1 up to Membrane 1.

Now you have three modules with granular jamming integrated in the central channels.