Jan 20, 2022, 12:20PM to 2:10PM
Welcome back. The main objectives for today are reviewing your precedent research and introducing some ad hoc pneumatic construction techniques.
- Please take a few moments to fill out the Office Hours Poll.
We’ll spend the first half of the class reviewing and discussing the works you found in the first assignment. There are a lot of posts to explore and we’d like everyone to have a chance, so we’ll keep the pace moving along. When your post comes up, please try to keep your explanation concise and focus on what specific elements you think will most inform the work of this class. As others talk, please always be thinking of the question you might ask.
We will randomly assign two or three per breakout room for a quick five-minute integrative discussion. Please discuss the work we’ve just reviewed and come up with a novel project idea inspired by the examples. No constraints at this stage: these could be extravagant and imaginative, but please include some elements of costume and air. Afterward, we’ll all meet again for a quick round of explaining your project idea.
Five-minute mid-class rest break. Please make sure your materials are handy when we return.
Ad Hoc Pneumatics
We asked you to gather the following materials:
- Pen, pencil, sharpie
- 3-5 ziplock bags (at least quart size)
- Double stick tape
- Scotch tape or clear packing tape or duct tape
- Straw or tube for blowing air
- Cardboard (can be from boxes)
- Useful, but not required: x-acto knife or box cutter
We will introduce the next assignment and demonstrate some basic approaches to making a kinetic structure which actuates fabric.
Our primary objective is to produce some kind of motion in fabric actuated by breath. We know you are working with ad hoc materials in diverse circumstances, so the point is to see what we can do within the constraints.
Some main considerations we will discuss:
- What is the closed chamber which constitutes the actuator? An actuator is any kind of device for translating movement or energy from one mode to another: an electric motor produces movement and force using electrical energy, a pneumatic cylinder produces movement and force using pressurized air. For this exercise, it could be as simple as a rectangular ziplock back taped with an airtight seal to a straw.
- How does the actuator shape change? A mechanical actuator performs work by producing a force acting through a motion. The force of pressurized air can be substantial as the air pressure is multiplied by the surface area (e.g. 1 psi breath multiplied by 10 sq in surface produces 10 lbs force). But coupling the movement to a mechanism requires identifying the specific shape modes. E.g., many simple pouches can act as tension actuators which shorten across the width as they inflate. Or with more constraint they can act as compression actuators which widen to separate other parts.
- How is that change of shape coupled to the fabric? It can be direct (e.g. pure inflation) or coupled through a rigid hinged structure.
- How is the motion reversed? Is there a spring action created by the fabric compliance or a component such as a rubber band? Does gravity act to return the motion?
- The second assignment is due before class on Tuesday.