What are the materials of force sensors?

What are the materials of force sensors? Force sensors are a kind of detection device composed of one or more elastic bodies that deform after being subjected to force. They are widely used in many fields such as machine tools, ships, petroleum, and industry. Today, the editor will mainly introduce the materials of force sensors. When we use force sensors, we need to know what materials they are. Let's take a look at the specific introduction.

Elastomer material

The elastomer material of the force sensor is generally made of metal, and most of the available materials are aluminum alloy, alloy steel and stainless steel. The alloy material has both rigidity to ensure consistent deformation and deformation recovery, and good weather resistance and corrosion resistance. The main requirement of the elastomer is to be able to accurately transmit force information and maintain deformation consistency and complete reset under the same force.

Strain gauge and resistor element materials

The composition of the resistance strain gauge is complex and it is a composite manufacturing product. The combination of the base material and the strain copper of the strain gauge is ever-changing. According to the strain requirements, there are nearly a thousand products at present. Generally, the base material is made of polymer film material and the strain material is high-purity constantan. The constantan on the base material is optically treated and then etched with different resistance grid wires that sense deformation. Therefore, the quality of the resistance strain gauge is not only related to the base material and the purity of the composite metal, but also to the composite process, etching technology and process, etching chemical materials and post-processing process and materials and other factors.

Patch adhesive material

The adhesives used for resistance strain gauge patches mainly adopt two-component polymer epoxy series adhesives. The performance of polymer chemical products is closely related to the physical and chemical indicators of each component, such as purity, structure and size of molecular chain, storage time, component ratio, molecular modification, mixing method, mixing and aging time, curing time, curing temperature, additives and percentage and other factors.

Sealant material

In the early stage of force sensors when welding technology and equipment were not sufficient, a special series of silicone rubber sealants were used. Silicone rubber has long-term chemical stability, so it has excellent properties such as corrosion resistance, moisture resistance, aging resistance, and insulation, and has long been the preferred product of all sealants.

Material of the wire of the force sensor

The wire is still part of the force sensor. The metal material of the force sensor wire has a personal experience of quality differences due to the use of wires in household appliances. After all, the wire is the path for bridge power supply, signal output, and long-line excitation voltage compensation. Silver-plated wire is definitely better than copper wire in terms of conduction effect, and copper wire is definitely better than aluminum wire in terms of conduction effect. Its role is self-evident.

With the increasing number of interferences such as various high frequencies and radio waves, excellent shielding of force sensors is also an important method to protect signal stability. In addition, environmental erosion, insect and rodent damage, fire retardancy, etc. also require the material of the sensor protection layer to be anti-corrosion, anti-insect, fireproof and explosion-proof, and even armor protection, casing protection and other methods are needed.

Wire sealing materials and methods

Each component of the force sensor will affect the final technical performance of the sensor. Some force sensors only use a simple fixing method to prevent the movement of the sensor wires and damage the sensor's electronic circuit fixation. Some force sensors with a very short conduction distance even rely solely on glue sealing for fixation. However, for force sensors with larger volume and heavier weight, if there is no proper wire fixing or sealing method, it is the bottleneck that is most likely to cause failure of the force sensor. In particular, when adding a sealing head to fix the wires, the material and tightening force of the fasteners will also affect the final technical performance of the force sensor. Observers have found that few fasteners are installed using sealing adhesives, which can avoid the residual stress caused by relying on the tightening force to fix, and will not cause leakage due to insufficient tightening force.