University of Silesia in Katowice

Would a smartphone survive in space?

| Weronika Cygan |

We are nearing a moment when spaceflight will cease to be available to a chosen few scientists and engineers. Soon we will send people to the Moon again. The next stop will be Mars. How will our electronics fare on those journeys?

The human presence in the vastness of space comes with many challenges. Not only the extreme conditions which the human body faces when outside of the Earth’s atmosphere, but solar radiation, vacuum, temperature or zero gravity affect the equipment and materials of which it is made as well. Under the “Freedom of research” competition organised by Research Excellence Initiative, Iwona Lazar, PhD from the Faculty of Science and Technology of the University of Silesia had a closer look at piezoelectrics. The physicist has researched how widely used materials behave in simulated outer space conditions.

Electrons under pressure

‘The piezoelectric effect has first been noticed by brothers Pierre and Jacques Curie in 1880. The word “piezo” is of Greek origin and means “pressure” the researcher explains and adds that a simple and reverse phenomenon can be distinguished.

In the simple case the pressure exerted on a piezoelectric material induces electric charge on its surface in the form of e.g. electrons. A reverse piezoelectric effect is observed when an electric field is appliedtoa piezoelectric and in response it changes shape. Not all materials show such properties – atoms in such materials are arranged in a way where unit cells lack an inversion centre.

Piezoelectrics found common use in many items of everyday utility such as lighters, car fuel injectors or microphones.

‘We can find them in speakers as well, where a changing electric field causes vibrations – the changes in shape of the piezoelectric – and in turn a translation into sound. A simple and reverse piezoelectric effect occurs also in USG, because the apparatus contains both an emitter and a receiver of ultrasound waves. Piezoelectrics are also used in precise steering of advanced scientific instrumentation, e.g. AFM (Atomic Force Microscope)  There even exist piezoelectric skis in which the energy generated during movement on the slope is accumulated, and in the right moment an electronic system stiffens the rear part of the skis, which results in acceleration’ enumerates Iwona Lazar, PhD, emphasising that these are just a few examples, and not even the most surprising ones.

The discussed phenomenon finds its use in the production of energy as well. Methods have been developed of converting vibrations or pressure into electric energy with the use of piezoelectric materials. In June of 2022 in Warsaw kinetic floor tiles were installed for a concert of the band Coldplay. The public, jumping and dancing, was generating electricity used to power the equipment during the event.

Even our everyday communication would not be possible if not for the use of piezoelectric elements. When talking into the microphone, our voice exerts pressure and is converted into electrical energy (this is a simple piezoelectric process). After reaching the recipient, a conversion of this signal into sound occurs in the speakers (a reverse piezoelectric effect). Not long ago a piezoelectric actuator for realising optical zoom in smartphones has been invented.

Iwona Lazar, PhD | private archive

A laboratory out of space

Piezoelectrics have found a use in space travel as well, for studying the cosmos. Many instruments e.g. on space stations of probes include components built from piezoelectric materials. Iwona Lazar, PhD points to their universal usefulness – Thanks to them, we are able to change the shape or the position of an object, controlling it from down on Earth through applied current. We do not need to send a human into space to do it. We can manipulate chosen elements from the surface of our planet. Repairing equipment is very costly and, in practice, means sending another manned mission into space. Conditions existent in the outer space demand that materials used in it be, among others, stable when working in a wide range of temperatures and in vacuum.

That is why the endurance of piezoelectric materials needs to be tested in extraterrestrial conditions and we need to find out how their “expiry date” can be stretched further – explains the physicist. It is known from research that in vacuum these materials degrade faster.

The topic of the UŚ scientist’s research, conducted within the framework of the “Freedom of research”, has crystallized while cooperating with experts in the fields of crystallographic defects Prof. Krzysztof Szot and of the piezoelectric phenomenon Prof. Krystian Rolender (both experts also work at the Faculty of Science and Technology) The scientists tested piezoelectric ceramics in different thermal and atmospheric conditions and electric fields. The aim was to find the mechanics responsible for the degradation of piezoelectric materials (electrodegradation), subjected to simulated vacuum of space. The tests were conducted at the Institute of Energy an climate research (IEK) in Germany – one of the largest interdisciplinary research centres in Europe, where the scientists from the University of Silesia went during the course of their research.

‘We have noticed that the conditions present in outer space accelerate the escape of oxygen from the studied piezoelectric ceramic, which is a symptom of the material’s degradation. At the distance of around a 100 kilometers from the surface of the Earth the pressure is about a million times lower than on the surface, as such the partial pressure of oxygen is near zero. As a comparison: the process of electrodegradation with the escape of oxygen from piezoelectric ceramic, occurring on Earth with a much higher partial oxygen pressure, occurred blisteringly fast in the vacuum of space’ explains Iwona Lazar, PhD.

High temperature also unfavourably affects the properties of piezoelectrics, which speeds up the process of electrodagradation of the ceramics, or even nullifies it’s effects entirely. The physicist explains, that even though the space is rather cold, instruments bearing the full brunt of the Sun’s rays may be greatly affected.

Iwona Lazar, PhD highlights that the results of her research are not limited in usefulness to the outer space and can easily be applied to develop better materials and equipment used on Earth.

Because we have reached the era of commercial spaceflight (albeit on a modest scale, limited by the size of people’s pockets) and we are approaching manned missions to other celestial bodies, we should be thinking on how our electronic devices will handle the vast universe. The thought of whether our smartphone can handle a trip beyond Earth may no longer be as abstract as it may have seemed.