SOFT ACTUATOR ORTHOSIS

A linear actuator, equipped with a plunger at its end, pushes into a custom-cut 20ml syringe, transferring the contents into the silicone body.

This offers the potential to utilize liquid instead of air, enhancing the efficiency of the device.

Sold as a pre-assembled kit that must then be formed by a professional to ensure a snug fit.

The splint will be available in different sizes based on the user's anthropometric measurements.

The structure housing the silicone body will be parametrically designed according to the length of the patient's index finger.

Both the PVC pipe and silicone body can be trimmed to the required size.

The splint is crafted from low-temperature thermoformable material. It can be soaked in water at 60-70 c° (140-158 f°) for one minute, making it pliable for easy manipulation. Once the layout is cut, the entire assembly is combined with the ABS components to ensure proper positioning during forming.

Layout cutting

Assembly

Heating

Forming

The user can adjust the width of the pinch by himself according to the object to be grasped.

To power on the linear actuator a 12V battery is needed. The PCB integrates a properly dimensioned voltage divider used to read the voltage drop across the battery. Battery state is shown through an RGB LED.

A supportive structure envelops the silicone, enhancing the control of bending and providing support points. 

Research aimed at optimizing energy transfer and relies on two main factors: the cross section of the body and the choice of material. The evaluation also considered the ease of reproduction.
The silicone selected has shore 13.
Once removed from the mold, the body is sealed with a piece of silicone-soaked cotton, which serves as a non-elastic layer. 

Cast

Ectract

Seal

Cut

For the realisation of the prototype, certain choices had to be made regarding the components to be used. The linear actuator selected is a 12V, we are currently investigating solutions to get to a 5V powered system in order to reduce the battery compartment size.