Producing piezoelectric tubes for heart pumps
Opportunity
According to the World Health Organisation, cardiovascular diseases are the world’s leading cause of death. Cardiovascular diseases often end in heart failure, or the reduced ability for the heart to properly pump blood. Worldwide, at least 26 million people are affected with heart failure. While transplantation is the treatment of choice for patients with end-stage heart failure, suitable heart donors are in short supply.
To overcome this shortage, ventricular assist devices are increasingly being used. These devices, also called heart pumps, are surgically implanted, helping the heart pump blood to the rest of the body. Historically, such pumps are large and heavy, limiting patient comfort and mobility. Moreover, as these pumps require an external power supply, the patient also becomes vulnerable to potentially deadly infections. This has led to a growing demand for small and lightweight heart pumps.
Tapping onto tubular piezoelectric components represents a promising strategy to resolve the issues associated with heart pumps. With piezoelectric components, mechanical energy from the motions of internal organs can be converted into electric energy to power the pumps. However, it remains difficult to ensure material uniformity with current methods of fabricating piezoelectric tubes. Hence, there is a need for an affordable method to accurately produce high-quality miniaturised piezoelectric tubes for heart pumps.
Technology
This invention describes a novel method of forming a multi-layered piezoelectric tube for use in a small and lightweight heart pump. The method relies on a process known as electrophoresis, where charged particles are deposited onto an electrode to create the desired film or coating.
In this scenario, a rod is positioned in a fluid medium containing piezoelectric ceramic particles and an electrode. Once a voltage is applied to the setup, the ceramic particles are deposited onto the rod to create the initial layer. This general process is then repeated to create the desired number of layers, after which the layers are treated with heat. This not only solidifies the particles on the rod’s surface, but also burns off the rod in the process. The end-product is a dense tube of solidified piezoelectric ceramic particles.
Unlike other techniques, electrophoresis not only has the ability to uniformly fabricate piezoelectric tubes, but it can also produce thin-walled, miniaturised versions. After all, the tubes’ thickness and morphology can be easily customised by changing parameters like rod diameter or even deposition time. Given its simple set-up, electrophoresis ultimately represents an economical way to produced piezoelectric tubes suitable for small-scale applications—including medical implants such as heart pumps.
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