#  Components 

 



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The soft sensor itself consists of three major components: The sensor body, the conductive interface to the fluid and the conductive fluid itself.

 ![components](/sites/g/files/omnuum4601/files/2024-11/components.jpg)

 

### The Sensor Body

The sensor body is a silicone rubber rectangular cuboid with a lengthwise circular channel with conductive rubber ends and rubber tubes to transmit pressure.

In practice, the sensor body can be any shape that is able to be cast using traditional silicone casting methods. The only limitation is the requirement of an internal cavity or channel to house the conductive fluid.

### The Conductive Fluid

The fluid used in this guide is simply saline (salt) water at 5 wt%. (5 g NaCl + 95 g water)

One major limitation of using an ionic fluid is the ion build up at the two conductive ends when measuring resistance using standard methods, such as using an ohmmeter. To circumvent this, the resistance must be derived from the voltage drop across the sensor from a low voltage alternating current source. This is similar to typical water conductivity measurement methods. More details are explained in [this](https://sandbox.softroboticstoolkit.com/f2875f32/design/subpage2) section.

### The Conductive Interface

An electrically conductive medium forming an electrical pathway between the conductive fluid and the external measurement system. Using conductive rubber as the interface, fabricated with chopped carbon fiber mixed with silicone rubber, we can reduce the drastic change in stiffness between the soft inner components and the wires of the measurement system. Another benefit of using this specific form of conductive rubber is the ability to cast it into any arbitrary form.

### **Bibliography**

Preechayasomboon et. al. [Multi-Modal Sensing and Actuation in Biomechanical Hydraulic and Pneumatic Systems.](/publications/multi-modal-sensing-and-actuation-biomechanical-hydraulic-and-pneumatic?admin_panel=1)

[Export Citation](/bibcite/export?content_filter%5B0%5D=1333742&format=bibtex)

### **Contributors**

Pornthep Preechayasomboon

Gaurav Mukherjee

Eric Rombokas