Goldbug is an insect whose exterior usually appears golden. When it senses any external stress like poking, it's responded by changing the appearance in reddish orange. It has been claimed that the 3D printed device shows similar characteristics when it stimulates by a mechanical stress.
However an abstract about the concerned project is published on MIT's own news portal, MIT News. Subramanian Sundaram, an MIT graduate in electrical engineering and computer science (EECS), who led the project.
According to science journal Advance materials technologies, they actually try to replicate sensorimotor pathways inside a 3D printed robotic skin. Sensorimotor is actually characterized by networks of sensors and interconnects.
Subramanian emphasized that in this project, they need the simplest organism that's why they choose Golden tortoise beetle to replicate. To get a similar effect, Sundaram and colleagues used 3D printed flexible circuitry deposited on the plastic substrate.
This 3D printed device is approximately T-shaped along with a wide, squat base and an elongated crossbar. The cross bar is made of an elastic plastic with a silver strip along its length. They connected electrodes at the end of the crossbar.
The base of the 3D printed device is constructed with more rigid plastic. It consists of two transistors and a circular semiconducting polymer. Researchers have abbreviated this semiconductor polymer as Pixel
Regarding the study, When the crossbars are stretched it changed the electrical resistance of the silver strips. Then this is resulting from the color change of the pixel.
For the 3D design, the researcher used the MultiFab, a custom 3D printer. It consists of two print heads. One head is for emitting hot materials and one for cool, and also featured with an array of ultraviolet light-emitting diodes. In addition, Sundaram used a copper-and-ceramic heater, which was necessary to deposit the semiconducting plastic.
The standard transistor consists of an insulator between the gate and the semiconductor. This is used to prevent the gate current from leaking into the semiconductor channel. In this regard, researchers are using the layer of potassium salt water to separate but it reduces the operating voltage. It implies that the device becomes less durable. So they have a future plan for using hydrogel instead of salt water.
