Micro coils: An overview on design, manufacturing and applications

Discover the world of micro coils and their manufacturing process in this comprehensive guide. Explore the various types of micro coils, the materials used, and their applications in the medical and sensor industries.

Micro coils are a demanding topic that engineers from the medtech and sensor technology industries should familiarize themselves with, and it pays to work with an experienced manufacturer.

Understanding micro coils: types and configurations

Micro coils are small, tightly wound coils that are used in various electronic devices. They can be classified into different types based on their configurations. One type is micro coils with air core, which are coils without any magnetic core material. These coils are lightweight and have low inductance. Another type is micro coils directly wound on magnetic cores, which have a magnetic core material such as ferrite or iron. These coils have higher inductance and are commonly used in applications that require higher magnetic fields.

The configuration of micro coils also plays a role in their performance. Some common configurations include solenoid coils, which have a cylindrical shape, and flat coils, which have a flat, pancake-like shape. Each configuration has its own advantages and is suitable for specific applications.

Overall, understanding the different types and configurations of micro coils is essential for designing and selecting the right coil for a particular application.

Micro coil manufacturing: wires and core materials

The manufacturing of micro coils involves two main components: wires and core materials.

For wires, commonly used materials include copper and gold. Copper wires are widely used due to their excellent electrical conductivity and affordability. Gold wires, on the other hand, are used in applications where high reliability and corrosion resistance are required. These wires are so incredibly thin, with diameters as small as 0.008 mm / AWG 58, that they are practically invisible to the naked eye during the manufacturing process.

When it comes to core materials, there are several options available. Some common core materials used in micro coils include ferrite, iron, and composite materials. Ferrite cores are popular due to their high magnetic permeability and low electrical conductivity. Iron cores offer higher magnetic saturation but have higher electrical conductivity compared to ferrite cores. Composite materials, such as powdered iron mixed with epoxy resin, can be used to tailor the magnetic and electrical properties of the coil.

The selection of wires and core materials depends on various factors such as the desired electrical and magnetic properties, cost considerations, and the specific requirements of the application.

Scale: 0.1 mm / Manufacturer: KUK Group

Applications in Medtech: From imaging to implants

Micro coils play a crucial role in various medical technologies, from imaging devices to implantable devices.

In imaging devices such as magnetic resonance imaging (MRI) machines, micro coils are used to generate the magnetic field required for imaging. These coils are carefully designed and positioned to produce a uniform magnetic field and enhance the sensitivity of the imaging process.

In the field of implantable devices, micro coils are used in applications such as neurostimulators and pacemakers. These coils are responsible for wirelessly transmitting power and data to the implanted devices, eliminating the need for physical connections. The small size and high efficiency of micro coils make them ideal for implantable applications.

Overall, micro coils are revolutionizing the field of Medtech by enabling advanced imaging techniques and enhancing the functionality of implantable devices.

Micro coils in sensor technology: Enhancing precision

Custom-made micro coils are also widely used in sensor technology to enhance precision and sensitivity.

In various types of sensors, such as pressure sensors and temperature sensors, micro coils are used to detect changes in the physical parameters being measured. The coils act as transducers, converting the physical changes into electrical signals that can be easily measured and analyzed.

The small size and high sensitivity of micro coils make them ideal for sensor applications where accuracy and reliability are crucial. They can be integrated into miniature sensor devices, enabling precise measurements in a compact form factor.

From automotive sensors to biomedical sensors, micro coils are playing a vital role in enhancing the performance and accuracy of sensor technology.

Challenges in micro coil manufacturing

Despite their numerous advantages, the manufacturing of micro coils also presents several challenges.

One challenge is the precise positioning and alignment of the coil windings. Micro coils require tight winding tolerances to achieve the desired electrical and magnetic properties. Achieving consistent and uniform winding is crucial for the performance of the coil.

Another challenge is the selection and handling of the core materials. The properties of the core materials, such as magnetic permeability and electrical conductivity, need to be carefully considered to meet the requirements of the application.

Roswitha Ritter, KUK Product Manager Medical & Sensors on core material choice for micro coils:

Furthermore, the small size of micro coils makes the manufacturing process more complex and delicate. Specialized equipment and techniques are required to ensure accurate and reliable production.

Overcoming these challenges is essential to achieve high-quality and high-performance custom micro coils.