Lab 1: Puppetry and Movement

Lab partner:Salma Kashani

1- 3D surface probe (1 mm)

     Goal: To design a Physical Surface Magnifier (PSM) that can measure the geometrical shape and surface properties of a mechanical sample. Using multiple probes, the information is gathered through exploiting the conventional mechanisms of “touch” and “feel”. Inspired by atomic force microscopy (AFM) with demonstrated resolution on the order of fractions of a nanometer, it is believed that PSM [can identify the surface, as well as capture how a sample as small as an ant would feel like. While only 3 probes are required to provide enough information to find the equation of a plane (geometrical shape), additional probes can scan concave and convex areas on the surface.

       Approach:To test the feasibility of the structure, we started by using wooden skewers and a piece of foam board. The friction between foam and skewers led us to use two metallic pads with holes through which skewers could freely move up and down. The reason was to limit the movement only in one direction. In this design the gravity and weight of skewers provide the force that is required for the movement. Finally, by adding heat shrinks we limited the range of displacement for each skewers. In our first prototype, we made our first 3D surface scanner with 16 bits resolution (16 skewers). The further steps would be to place the skewers in an angle so they can also magnify the surface.

(photo courtesy:Salma Kashani)

2- Soft robotic finger (10 mm)

         Goal:To sketch a flexural design of an under-actuated finger (one actuator for two joints).

(photo courtesy:Salma Kashani)

         Approach: In the first iteration, we tried to use a plastic tightening strap as the body of the finger and fold it to make the joints. By routing a nylon strand through joints and then pulling it, we attempted to bend the finger. Obviously, since the thickness of the body of the finger was as same as the joints, we observed deformation of the finger. For our second iteration, we tried to solve that problem by having more flexible joints in which the required bending force is much higher than the maximum resistive force that the finger can tolerate. To achieve this goal, we used a rubbery tube as the body of the finger and then cut two triangles at the joint parts. At this point, we could see the finger bent through pulling the nylon strand. Next, we made a stand for the finger and used an O-ring to make the pulling action much easier.

3- Paper airplane launcher (~100 mm)

           Goal:To launch a paper airplane using rubber band.

(photo courtesy:Salma Kashani)

         Approach:Our paper airplane launcher is a simple design. The launch platform is made of a rubber band which is stretched between two metallic parts that are fixed to a piece of a foam board. Using a wood skewer, we kept the rubber band at a highly stretched position so that by pulling it out, we can release the rubber band, and launch the paper airplane. Second piece of foam with 1mm wide cavity at the center was used to hold the paper plane in position, and guide it through the launching process.