NUS researchers have revolutionised a way for wearable devices to interconnect. They have integrated conductive textiles into clothing to effectively connect several wearable devices at once. These clothing contain a wireless body sensor network which allows devices to transmit data with signals 1,000 times stronger than conventional technologies. This wireless network of wearable devices could be used in the future for health monitoring, medical interventions, and human-machine interfaces.
At present, most body sensors such as smartwatches connect to smartphones and other wearable electronics via radio-waves like Bluetooth and Wi-Fi. The outward radiation of these waves in all directions means that most of the energy is lost to the surrounding area. This greatly reduces the efficiency of wearable technology as most of its battery life is wasted in trying to make the connection.
The team of researchers from the Institute for Health Innovation & Technology (NUS iHealthtech) and NUS Engineering came up with a solution to this problem – enhancing regular clothing with conductive textiles known as metamaterials. These metamaterials are able to create ‘surface waves’ which can move wirelessly around the body of the clothes. The energy of the signal between devices is held close to the body rather than spreading in all directions. As a result, the wearable electronics use much less power than usual and the devices are able to detect weaker signals.
The signal between the devices is so strong such that power can be wirelessly transmitted from smartphones to the device itself. This provides a window of opportunity for battery-free wearable devices.
Assistant Professor Ho, who is a part of the research team said, “This innovation allows for the perfect transmission of data between devices at power levels that are 1,000 times reduced. Or, alternatively, these metamaterial textiles could boost the received signal by 1,000 times which could give you dramatically higher data rates for the same power”.
With this technology, smartphones and Bluetooth devices do not need to undergo any changes. The metamaterial works with any current wireless device in the designed frequency band.
Privacy is also enhanced with this technology. As mentioned above, the current use of radio-waves transmits signals outwards from the person wearing the device. As a result, personal and sensitive information is vulnerable and could fall into the hands of others. This new form of technology is more secure by allowing the confinement of the wireless communication signal to within 10 centimetres of the body.
Design and features
The metamaterial textile design consists of a comb-shaped strip of metamaterial on top of the clothing and with an unpatterned conductor layer underneath. The strips can be arranged on the clothing in any pattern to connect all areas on the body. The clothes which are produced with this design will be robust. They can be folded and bent with minimal loss to signal strength. The conductive strips can also be cut and still would not inhibit wireless capabilities. This clothing can also be washed and ironed like regular clothing.
Plans for the future
The research team is looking to commercialise the technology. They hope to test this new form of tech textile to produce specialised athletic clothing such as allowing the athlete to adjust the volume on their wireless headphones with a single hand motion. They also envision of producing clothes for hospital patients, to monitor their health. This technology could be used to measure a patient’s vital signs without hindering their freedom of motion.