Digital hinge is an interactive textile functioning as material interface between the physical and the digital realm. The projects investigates ways of bridging the material behaviour of reconfigurable surfaces with real time digital models, transforming physical interactions into data and accurate representations.
The textile design is based on a Resch’s modular pattern. The tessellated surface is divided into stiff triangular regions and soft hinges, which allow the structure to bend when physically manipulated. A variety of composite techniques were investigated to obtain the two features as an homogeneous surface with a smooth finish. The stiff triangular features were obtained through layering lasercut custom shapes impregnated with epoxy resin on a flat fabric substrate. The hinge areas are preserved thanks to a rigid lasercut frame. The material was then placed under a vacuum press to cure and to eliminate the excess material.
The sensors were encapsulated in a thin layer of resin to protect both their fragile wire connections and the flexible vynil-cut conductive traces they were layed onto. Each sensor was then paired with a neodymium magnet. The magnets were casted directly on the composite surface after the vacuum curing process. Placed in correspondence of the sensors on the opposite sides of each soft hinges, each pair functioned as a fold detecting unit capturing the angle between the origami tessellations.
Each module is provided with 3 sensors and the data is collected through an Attiny44 microprocessor, and transmitted by the custom designed board via serial communication to the digital system. Each module is conceived as a unit provided with an identity, that can be connected to other modules to create a wider sensing area. Functioning as a wired network communicating asynchronously in a bridge-nodes configuration, each module is able to respond to its id, and selectively send and receive information to/from the digital interface via FTDI.
The digital system is implemented through a variety of tools. The board is programmed through Arduino IDE and it interfaces with Grasshopper and Firefly via serial port. The digital simulation of the physical behaviour of the surface is implemented though Grasshopper and Kangaroo.
The simulation is based on a simple Rhino definition of a geometric mesh corresponding to the Resch pattern design used for the physical prototype. Valley and mountain folds are also determined by the system, together with the maximum folding angle for each of them. The sensor data is processed in the digital environment, matched to the relevant valley/mountain folds and converted into forces that are applied to the hinge folding behaviour. Kangaroo acts as a live physics engine, where each digital hinge responds separately and in real time to the physical manipulation happening on the surface, bridging the materiality of the prototype with the digital interface.
Digital Hinge was conceived as a platform for investigation of the naturalisation of the relationship between digital and physical interfaces. It functions as a framework for new material systems rather than as a finished product. Within such framework, the prototype is intended to evolve in its physical form through future iterations, by replacing current with smarter materials and sensing technologies, towards more ‘seamless’ applications.