What are Flexible Circuits? Why are they used in Medical Devices?

Today, flexible circuits are gaining priority over traditional printed circuit boards. These circuit offer significant benefits of space-saver designs, weight, and cost savings over PCBs. Also, these circuits have the potential to reduce the use of wiring by 75%, and costs of electrical interconnections by 70%. All these benefits make them appropriate for medical devices, which demand high precision. This post discusses increased use of flexible circuits in medical devices.

6 Reasons Why Flexible Circuits are Preferred in Medical Devices

Design, development, and manufacturing of medical devices are mainly influenced because of two interrelated technology trends – miniaturization, and use of flexible circuits. As a device gets more and more complex, it is more likely to include complex electronic systems. On the other hand, as a device gets increasingly smaller, it is more likely that the size of circuit will shrink. These are the challenges faced by the manufacturers of medical devices. However, flexible circuits are addressing the challenges faced by the manufacturers by allowing them to manufacture smaller devices with compact circuitry. Here are the six main reasons why flexible circuits are used in several medical devices:

1. Dynamic Flexing: Flexible circuits have an exceptional ability of dynamic bending or movement. This property is beneficial for applications having interconnection through a hinged device. It also helps to maintain connection through devices that expand, contract or telescope during their application.

2. Reliability: Flexible circuitry has a proven performance of nearly 20 years in high demand medical applications. It has increased the confidence of medical industry in flex circuitry’s reliability and robustness. Flexible circuitry has characteristic advantages since it eliminates connection points, thus simplifying assembly and eliminating chances of interconnect defects such as poor solder joints.

3. Bio-compatibility: The materials that are used in flexible circuits are bio-compatible in an array of applications. Implantable devices are fully sealed to reduce contamination, whereas non- implantable devices are used in applications that require contact with human skin.

4. Space and weight: Growing demand for smaller and lighter devices in the medical industry makes flexible circuits a perfect choice in applications when space and weight are a problem. Flexible circuits are thin, and can easily be bent to adapt to tight spaces, while interconnecting several planes. These circuits are lighter as compared to rigid boards.

5. Feature Density: The flex circuits can be built with fine lines, spaces, and are constructed with several layers. This becomes increasingly significant since designers are continually reducing volume, and increasing functions.

6. Cost: As flexible circuits decrease the number of connections required, they can be manufactured efficiently in high volume. This helps reduce the assembly costs. Eliminating soldered wires, rigid printed circuits, and connectors, are possibilities that further lessen total cost in an interconnection design.

Applications of Flex Circuits in Medical Devices: 

Flex circuits are widely used in several medical devices, including:

• Surgery Tools: The surgical tools consist of screw drivers, electronic saws, and cauterizing scissors for clamping and closing blood vessels during the surgery.

• Implantable Medical Devices: The non-implantable medical devices consist of cochlear implants (hearing), pacemakers, neurological implants, and defibrillators. These devices are implanted surgically in a human body. Flexible circuitry is used as the product requirements include extreme durability, reliability, light weight, and compactness in size.

• Non-implantable Medical Devices: These devices include external defibrillators (attached to patient), drug dispensing systems, and hearing aids. These devices are typically worn or attached to the skin of a patient.

• Diagnostic Equipment: This are the equipment that do X-Ray’s, ultrasound scanning, CT scanning, MRI’s, and other types of equipment that help detect and diagnose different health problems.

• Monitoring Devices: Monitoring devices comprise portable or wearable electronic devices that monitor blood sugar rate, heart rate, body temperature, and blood pressure. Bedside monitoring devices are also included in this category.

The technology of flexible circuit is all set to provide a lot of design freedoms for product designers and medical equipment manufacturers in upcoming years. As modern electronic systems starts demanding better environmental performance, increasing functionality, higher connectivity, greater circuit density, and that too at lower cost, flexible circuit technology is expected to address all these demands.