The Use of Different Materials for Micro-Coil Winding Technology
Table of Contents
Micro-coil winding technology is necessary for the production of inductive components of tiny medical devices. This technology utilizes an ultra-fine wire to wind around a specific-shaped support or a core or pin. Even though the winding process is the core method to prepare the components, manufacturers also handle several other activities, such as insulating the tiny copper wires or other conductive wires and connecting the wires and the components within the medical devices. This technology engages the thermo-pressure bonding method to join 9-micron-ultra-fine wires. The diameter of these wires is five to twelve times thinner if you compare this with the diameter of a human hair.
The parameters, such as the size and shape of the coils can vary based on the application area. For different application areas, the required resistance, magnetic field strength, and inductance change. Similarly, different customers also have different requirements regarding the use of materials for the production of micro-coils. However, it is important to consider the application carefully in order to select the suitable material for that application.
Materials and Their Characteristics:
Copper, titanium, stainless steel, and aluminum are the common metals that get used to prepare ultra-fine wires. However, in some critical application areas, precious metals with excellent purity, including platinum and gold are useful.
- Copper:
Copper is the second-best conductor after silver. Copper’s excellent physical properties and high conductivity are useful for various medical applications. Copper wires are also extremely reliable and durable. This is why in several applications, manufacturers use copper and copper alloys. However, the use of coating or enameled wire is essential to safeguard copper wires from external damage. Depending on the purpose of use, manufacturers determine the type of coating.
- Aluminum:
Aluminum metal is lightweight. Therefore, when it comes to building micro-coils for portable medical devices, manufacturers use aluminum metal wires. An aluminum coil remains very lightweight even after a large number of turns during the winding process. However, these coils are quite expensive because of high manufacturing and coating costs. The high production cost is accountable for the rare use of these coils.
- Stainless Steel:
The use of stainless-steel wires is beneficial for various reasons, such as high durability, strong yet lightweight, complete recyclability, heat and corrosion resistance, etc. Stainless coils are mainly convenient for heating purposes. For instance, stainless steel coils are efficient for the defrosting of cancer tumors in cryotherapy treatments. These coils are also useful in corrosive environments.
- Titanium and Titanium Alloys:
Titanium coils have a variety of medical applications because of their outstanding corrosion resistance ability. These coils are beneficial for their non-magnetic properties which you can not expect from other ferromagnetic materials. To prepare devices for dental and other medical treatments, titanium coils are useful for their lightweight and higher strength compared to weight.
- Precious Metals with Excellent Purity:
In some rare medical applications, coils with precious metals, including gold and platinum are used. These coils are not only highly conductive but also awfully chemical resistant. When it comes to building medical devices that come directly in contact with skin or tissue, these coils are necessary. If you need to follow the FDA regulations and make biocompatible medical devices, these coils are effective. Because of high production costs, these coils have some rare applications, especially in some life-threatening situations.
Challenges and Solutions for Micro-Coil Winding Technology:
The micro-coil winding technology is associated with various non-trivial challenges due to the tiny thickness of the wires and miniature-sized coils. A long list of environmental and physical factors can also impact the winding method of micro-coils. To meet the strict tolerance requirements for the final products, manufacturers utilize custom-made machinery and innovative technologies.
Besides these production challenges, manufacturers also face some additional challenges when it comes to placing the coils suitably into the larger systems and connecting them with other components of the system. When traditional heat-based welding and soldering methods create various undesirable side effects, modern manufacturers hinge on thermo-pressure bonding methods for the connectivity solution between the components and the wires. If you use traditional techniques, you will witness excess strain at the joints, degraded connections, heat damage, and inferior joints. Therefore, it is important to apply the thermo-pressure bonding method to get excellent durable, and strain-free connections.
