Breakthrough: Organic Films Developed to Power Cardiac Pacemakers

UrFU scientists, together with colleagues from the University of Aveiro (Portugal), have succeeded in obtaining biocompatible crystalline films. They have high piezoelectric properties – they generate an electric current under mechanical or thermal stress. This property will be useful in the design of elements for invasive medical devices, such as pacemakers. Detailed information about the films obtained and the new method of their synthesis has been published by the scientists in ACS Biomaterials Science & Engineering. The research was supported by the Priority 2030 program.

“We have succeeded in obtaining films from diphenylalanine that have high piezoelectric properties comparable to their inorganic counterparts. Under mechanical or thermal stress, these films generate electricity. The use of such films will be particularly useful for making invasive cardiac pacemakers – devices that reside inside the human body. When the heart moves or beats, these films generate electricity, which is stored in the pacemaker’s batteries. Energy storage devices based on such materials could solve the problem of replacing depleted batteries and reduce the number of surgical procedures,” explains Denis Alikin, Head of the Laboratory of Functional Nanomaterials and Nanodevices at the UrFU Research Institute of Physics and Applied Mathematics.

Diphenylalanine is a form of phenylalanine, one of the 20 amino acids that make up proteins and play an important role in biological processes. This substance is part of the human body; therefore, Diphenylalanine materials are highly compatible with living body tissues.

“Inorganic analogs risk rejection because such materials do not integrate well with biological objects. As an organic material, diphenylalanine is biocompatible, which is important for creating both invasive and non-invasive devices. For example, sensors made from organic material worn by a human will cause less irritation than analogs made from inorganic polymers,” explains Denis Alikin.

Scientists synthesized the films using a new method – crystallization from the amorphous phase under the influence of water vapor. The traditional method of producing diphenylalanine involves crystallization in aqueous solution, which leads to the formation of structures with poorly controlled morphology.

“Previously, our colleagues found high piezoelectric coefficients in diphenylalanine. But the problem is that it is difficult to make films with a flat morphology from this substance because in solution diphenylalanine assembles into tubular structures. This posed a major problem because in the production of microelectronic devices, the surface of the film must be flat so that electrodes can be applied to it. The method we developed solved this problem – we were able to obtain films with a flat morphology. It should also be noted that our method is unique and has not been proposed by other research groups,” adds Denis Alikin.