The Reading I choose is 3D Printing Pneumatic Device Controls with Variable Activation Force Capabilities. It’s a paper documenting how a team developed rich haptic pneumatic buttons.
The two most important features of the invention are “not expensive” and “rich haptic”. The reason why it’s not expensive is that the production process mostly relies on 3D printing, which is time-consuming but cheap compared to go to a factory. In the rest of the paper, it introduces the design behind to explain how the rich haptic is reached.
The design – Preparation of the Production
The structure consists of a pressure source that provides gas to the system, two valves that are activated based on the user reaction, a pressure sensor that detects the user reaction, and the 3D printed chamber that functions as the user interface. When the sensor detects the pressure change, the valves will be open so that the button can be inflated and create the different resistance to the button.
Considering the conductivity, the team decided to use some components that already exist in the market since it’s hard to 3D print conductive thing nowadays.
The team explored several ways to inflate so as to give various haptic feedback to the user. These are for different interfaces, like slides, switches, and buttons.
There are also several shapes designed. Different shapes have the different capability of holding the pressure, thus, they would be used in different situations. Normally, a rounded shape can hold more pressure than an angled shape.
After this detailed preparation, the fabrication is needed. The main technology the team uses is Multi-material Photopolymer 3D Printing. However, a problem is that for 3D printing, the machine will automatically (or has to) build some gel-like support for the empty space of the structure, which means that the team has to tear off these parts afterward. It would be easy to do for the outside, but for the tube, it would be a disaster. Thus, the team comes up with four methods to solve this problem.
The first method is to divide the piece into several parts to 3D print. This would ease the work of tearing off the support, however, the hermeticity of the structure would be a problem. To avoid that, the team came up with the second method. Instead of 3D print the tube and some other structures, they could find these components from the market. The advantage is that since these components are from the market, the size will be fixed and it will be easier to control the size of the whole thing and it will be hard for the gas to leak.
For more geometric shapes, the team decides to use auxiliary support made from acrylics, this would not only further ease the job, but can also give some support to the structure so that it’s more firm.
The fourth method is very straightforward, which is to create a personalized tool to help tear off the support for the printed structure.
As shown in the picture, the final product is a combination of 3D printed components and found materials.
Besides using them in a toy, it can also be used in many other interactive devices that uses haptic interaction. In addition, because of the way it’s produced, it can also be duplicated by ourselves just by using silicone or 3D printing as well.