A new nanotechnology development promises to make batteries in pacemakers obsolete and make it possible for cars driving down the street to turn on the streetlights.
An international research team led by Tel Aviv University researchers will make it possible to generate electric currents and voltage within the human body through the activation of various organs (mechanical force).
The development involves a new and very strong biological material, similar to collagen, which is non-toxic and causes no harm to the body’s tissues. This nanotechnology innovation has many potential applications in medicine, including harvesting clean energy to operate devices implanted in the body (such as pacemakers) through the body’s natural movements, eliminating the need for batteries.
The project leader, Prof. Ehud Gazit, said they have found a long sought-for substitute for collagen, the most prevalent protein in the human body, which is useful in many applications.
“We used nanotechnological means to engineer a new biological material, a tripeptide – a very short molecule called Hyp-Phe-Phe consisting of only three amino acids – capable of a simple process of self-assembly of forming a collagen-like helical structure that is flexible and boasts a strength similar to that of the metal titanium.
“In the present study, we sought to examine whether the new material we developed bears another feature that characterizes collagen – piezoelectricity. Piezoelectricity is the ability of a material to generate electric currents and voltage as a result of the application of mechanical force, or vice versa, to create a mechanical force as the result of exposure to an electric field.”
In the study, the researchers created nanometric structures of the engineered material, and with the help of advanced nanotechnology tools, applied mechanical pressure on them. The experiment revealed that the material does indeed produce electric currents and voltage as a result of the pressure. Moreover, tiny structures of only hundreds of nanometers demonstrated one of the highest levels of piezoelectric ability ever discovered, comparable or superior to that of the piezoelectric materials commonly found in today’s market (most of which contain lead and are therefore not suitable for medical applications).
Discovery of piezoelectricity of this magnitude in a nanometric material is of great significance, as it demonstrates the ability of the engineered material to serve as a kind of tiny motor for very small devices.
Prof. Gazit adds: “Most of the piezoelectric materials that we know of today are toxic lead-based materials, or polymers, meaning they are not environmentally and human body-friendly. Our new material, however, is completely biological, and therefore suitable for uses within the body. For example, a device made from this material may replace a battery that supplies energy to implants like pacemakers, though it should be replaced from time to time. Body movements – like heartbeats, jaw movements, bowel movements, or any other movement that occurs in the body on a regular basis – will charge the device with electricity, which will continuously activate the implant.”
At this stage, the focus is on the development of medical devices, but Prof. Gazit emphasizes that “environmentally friendly piezoelectric materials, such as the one we have developed, have tremendous potential in a wide range of areas because they produce green energy using mechanical force that is being used anyway. For example, a car driving down the street can turn on the streetlights. These materials may also replace lead-containing piezoelectric materials that are currently in widespread use, but that raise concerns about the leakage of toxic metal into the environment.”
Also taking part in the study were researchers from the Weizmann Institute and a number of research institutes in Ireland, China and Australia.