The unknown piezoelectric property of diamond and the discovery of flexible membranes

Scientists from the University of Hong Kong have discovered that diamond, one of nature's hardest materials, generates stable voltage signals and exhibits a piezoelectric effect when thinned sufficiently and transformed into a flexible membrane.

The Unknown Property of Diamond

Scientists at the University of Hong Kong have brought to light a new, unknown physical property of diamond. It has been determined that diamond, which has been accepted as one of the hardest structures in nature since the 1900s, can generate electricity.

This material, previously thought incapable of generating electricity directly through mechanical deformation, successfully produced stable voltage signals when given an ultra-thin and flexible structure.

Edge Peeling Method

Researchers developed a special edge peeling method to transform polycrystalline diamond into a bendable, thin membrane. Thanks to this method, reproducible electric currents were obtained when the material was flexed.

The findings obtained showed that diamond, known as a passive support element in materials science, can now be evaluated as an active energy source.

Charge Polarization at Crystal Boundaries

When this flexible membrane, composed of multiple small diamond crystals at the micro level, is bent, an asymmetrical charge polarization occurs at the crystal boundaries.

As the intensity of the bending increases, a voltage difference is formed between the upper and lower surfaces of the membrane, and this process turns into a regular piezoelectric response.

Potential Use for Medical Devices

The fact that diamond is biologically highly compatible with the human body, non-toxic, and chemically corrosion-resistant makes this discovery critical for the medical field.

In the future, these membranes are anticipated to serve as the main power source in medical devices implanted in the human body that do not require battery replacements.