It is not only in summer that it can get hot during sports activities, because sport during winter also hasits pitfalls. Outside it is freezing cold, and insulating clothing is a must. However, if you move around a lot, your body's own "AC" kicks in: The skin releases liters of cooling sweat. To ensure that we don’t freeze in our wet clothes during our well-earned breaks, Empa researchers, in collaboration with industrial partners, have developed an electro-osmotic membrane, which keeps clothing (and the athlete) dry and thus warm.
The Swiss high-end sportswear company KJUS has integrated the technology into a ski jacket that can be operated by a smartphone. In experiments in Empa's climate chamber, the researchers also conﬁrmed the functionality and wearing comfort of the jacket with a "pump effect".
With the cardiobelt made of cuddly tissue and embroidered electrodes, physiologically important parameters can be measured comfortably over a longer period of time.
Products and exhibitors around wearables
Exhibitors and products related to this topic can be found in the catalogue of MEDICA:
Whether jackets and pants are comfortable to wear and release body heat effectively is now predictable thanks to virtual modeling. Empa scientist Agnes Psikuta and her team from the "Biomimetic Membranes and Textiles" lab in St. Gallen have developed software that takes into account fabric characteristics, the body physique and insulating air cushions between skin and clothing. "Using an anatomically customizable avatar, it is possible to simulate how an item of clothing ﬁts perfectly on the body and what thermal effects it has, even when the person is moving," explains Psikuta. Thus, a design for a suit can be optimized on the avatar before it is sewn from actual fabric.
Other high-tech garments are also ideal for use in state-of-the-art medicine. For instance, even when we are seemingly immobile, say, when we sleep, numerous muscles are active: The heart beats ceaselessly, and the chest rises and falls. But how does the heart beat during sleep? And does our breathing pause, or does it ﬂow calmly and steadily through the night? Empa researchers have developed a cardio belt, which, thanks to embroidered electrodes, can register heart activity throughout the night. Using the Empa plasma coating facility, nanometer-thin metallic layers were applied to the threads, making them conductive, skin-friendly and washable. The ﬂexible measuring device is used, for example, for people who suffer from respiratory arrest during sleep, so-called sleep apnea. Further clinical applications of the sensor belt are currently being developed with partners from industry and the medical sector. For example, the ECG belt – complemented by sensor technology for measuring body temperature – is intended to support the diagnosis of dementia such as Alzheimer’s, since the long-term measurement of vital parameters can provide information on cognitive performance.
Together with researchers from the Université de Haute-Alsace in Mulhouse, Empa researchers are also working on equipping textiles with additional sensors. In this way, the range of applications in medicine and sports and the wear comfort can be extended even further. "We will equip a piece of clothing, such as a T-shirt, with sensors for the analysis of various health parameters," says Simon Annaheim. The core element for the measurement of other parameters such as respiratory rate or oxygen saturation are optical polymer ﬁbers produced by melt spinning.
Since the micro-design of textile ﬁbers can be precisely controlled by various spinning processes, Empa researchers are also developing membranes that resemble biological tissues. For example, polymer membranes made of highly elastic core-sheath ﬁbers are colonized with human cells so that a multi-layered, functional tissue can grow. This research is part of the "Zurich Heart" project, on which Empa is working together with the University of Zurich, ETH Zurich and Zurich University Hospital. The "living" membranes are intended to line the inner surface of artiﬁcial heart pumps as “camouﬂage”, so that the body can better tolerate the device and malfunctions can be avoided.