Silicone injection is used in a variety of manufacturing processes in today’s industry; as such, one can appreciate the need for automation. The purpose of the device was to automate the silicone injection process by the use of mechanical parts, electronics, sensors and a microcontroller. Although there are several types of silicone curing methods, this project focuses on the application of the RTV (room temperature vulcanized) two part silicones.

The system was fabricated at UMass MRRL (Mechatronics and Robotics Research Lab). The gun assembly, silicone cartridge and a few other standard components were procured online. The system composed of a 6 part assembly including: linear actuator, double piston, holder/stand, static mixer, sensor - linear potentiometer and the 3D printed mold of a robotic bust.

The idea behind the automation was to use a closed loop feedback PID control to regulate the actuator speed and hence the flow of the silicone (flow area remaining constant) to adapt to changing conditions such as flow blockages simulated by a pinch valve in the system. PIC microcontroller and H-bridge were used for bidirectional actuator control and a linear potentiometer was integrated with the gun assembly to monitor displacement of the actuator.