With the rapid development of science and technology, human-computer interaction has gradually integrated into our lives. Whether we are using electronic products such as mobile phones, computers, or smart bracelets, we are all engaged in human-computer interaction.
Have you ever thought about it in the near future:
Mobile payment no longer needs to be swept, only need to gently stroke the sleeve to pay safely;
No longer use smart bracelets to monitor your health, you just need to put on clothes to get your physical signs data in real time;
Keys are no longer needed to start the car, just need someone to sit on the seat, the car can recognize your clothes and follow your commands;
......
These sci-fi and fanciful imaginations have now been made reality by scientists.
Recently, the team of Professor Peter Tseng of the University of California integrated advanced magnetic metamaterials into flexible textiles to create a system that can communicate battery-free between clothing and nearby devices.
The textile allows the wearer to digitally interact with nearby electronic devices, such as paying safely by simply touching or scratching the sleeve, and continuously monitoring and transmitting vital signs.
Source: Nature Electronics
The research paper, titled "Textile-integrated metamaterials for near-field multibody area networks," was published in the scientific journal Nature Electronics.
"Add" an NFC to the wearable
In 1975, the first calculator watch came out, and smart wearable devices began to enter our lives.
With the development of technology, more and more smart wearable devices appear in our lives, such as smart bracelets, smart glasses, smart fabrics, etc.
These smart wearables allow people to process external information more efficiently and monitor human activity or health.
Currently, human health monitoring and activity tracking technologies rely primarily on wearable or implantable sensors. The multi-node networks created by these sensors can interpret information from our interactions between our bodies and objects.
To parse this biometric information in real time, such a network requires a secure and reliable communication link between nodes, often referred to as body area networks (BANs).
Creating BANs requires connecting multiple sensors around the body, and in order not to restrict the movement of the human body, most of these sensors use wireless connections.
Traditionally, BANs have configured wireless communications that include custom RF sensors, RFID, or Bluetooth, but these radiation methods often present problems with high power consumption and low security (such as being eavesdropped).
The use of near-field communication (NFC) can effectively solve the above problems and improve the security of communication.
So what is NFC technology?
NFC is an RFID technology found in most smartphones. For example, when you pay with a smartphone or credit card close to the card reader, you take advantage of near-field communication technology.
NFC can be used both to power a device and to collect data from the device.
Therefore, this technology has the potential to eliminate the need for batteries from wearable sensors, making devices lighter, longer-lived, and less expensive.
Behind the seemingly "perfect" of this technology, there is a fatal drawback, that is, the communication range is too small, and only a few centimeters of short-distance communication can be achieved.
Using this technique on the human body, it is difficult to establish a connection to the whole body. (After all, everyone is a leg length of one meter eight, manual dog head)
To solve this problem, the textiles developed by the researchers expand the range of NFCs by using signals that can propagate orbits with minimal loss.
Figure | BN based on textile integrated metamaterials. (Source: Review article of the paper)
Signal transmission "in all directions"
Inspired by the current production of low-cost vinyl clothing, the researchers integrated magnetoelectric induction networks on textiles.
This approach skips the complex sewing techniques required for flexible fabrics for modern wearable devices, as well as expensive wires.
And magnetic metamaterials make it possible for signals to propagate along orbits:
These orbits are controlled by individual constituent units with artificial cycles, each consisting of an inductor and a slotted ground plane, which are connected together by fixing them to the fabric, and the adjacent inductors overlap to form a structure called a magnetic induction waveguide.
When an NFC reader is close to any cell, it can excite the voltage and current within that cell, which in turn excites adjacent cells, creating a coupling effect.
This coupling effect allows the signal to cascade along the entire structure, which can be described as a propagating wave.
Figure | textile integrated magnetic induction path. a. Resonator manufacturing and textile integration steps. b. Enlarged image of the resonator displaying its stack. C. Various flexible resonator designs to achieve the best signal transmission and power distribution. d. The wearable modular network is integrated into the garment and covered by a transparent heat-conductive vinyl as a mechanical fixture. The resonator can be designed to cover a wider area of the near field and can be embedded in a vinyl design with special colors. This allows network customization features and styles. f. The battery-free NFC transponder is integrated with the strain and temperature sensor to transmit the respective sensor status to the NFC reader. (Source: The paper)
The researchers used this effect to create trajectories that traverse the body, split into multiple branches, and cross the gaps between different pieces of clothing.
They liken the technology to a "railway, which can transmit electricity and signals when it crosses over a piece of clothing.
Not only can the system easily add new sections, but it can also "talk" to each other with different clothes.
In particular, they note that NFC readers in their trouser pockets can power off-the-shelf sensors placed on the chest, abdomen, knees, and ankles.
Professor Peter Tseng shows: "This means you can put your phone in your pocket and just rub other textiles or readers with your body, and electricity and information can be transmitted on your device." ”
This innovative design is highly flexible, and in sports, the pants can measure the movement of the legs while communicating with the tops that track heart rate and other statistics. Two people wearing this outfit can exchange the letters "high-five" by tapping their wrists against each other.
First author Dr. Amirhossein Hajiaghajani said there are countless medical applications for this technology, such as freeing hospital staff from the task of applying a large number of patient sensors, because these sensors can be integrated into medical gowns equipped with metamaterials.
Professor Peter Tseng said, "When you suspend your clothes on a wireless reader, the electronic devices send signals, so you can share information with a simple high-five or handshake. ”
Figure | uses textile integrated waveguides for multi-transponder and multi-band communication. a. Shirts and pants above and below the pants/shirt terminal. The NFC reader receives information from multiple sensors and connects to an external battery. b. Real-time, short-term and low-speed monitoring of human activities is achieved through time-minute-based multi-sensor readings in BANS. c. High-speed, long-term indoor walking/running activity measurement. d. Monitor the sensor during indoor operation under different speed profiles. e. Long-term packet loss monitoring during indoor operation. Body-to-body communication is achieved through the plug-and-play characteristics of NFC and its transmission measured when the hand is pulled closer and farther away over a long period of time to obtain various VD values. (Source: The paper)
The researchers say the textiles they developed are low-cost, simple to make, and can be combined with interesting wearable designs. Not only that, they hope that this design can reduce the burden that modern electronic products bring to our lives.
Ointment
The invention of this technology is refreshing, but there are still some problems that need further research.
The clothes we wear every day are not disposable, so the durability of this fabric is worth considering. The researchers say the textile can withstand a washing cycle, but to withstand daily wear, a more robust conductive material may be required.
Second, the interaction of fabrics with more readers or sensors is still a development direction. Whether smartphones and skin-mounted sensors can replace board prototypes to achieve similar performance remains an open question.
Technology makes our lives more intelligent, and in the future we will no longer be satisfied with the connection between machines and machines, the conversation between people, and more the interaction between people and machines.
Through human-computer interaction, we may be able to communicate silently like the Avatars in "Avatar"; we may no longer have to use mobile phone screens, and we can operate devices only through gestures; the development of science and technology will surely bring us more convenience.
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Author: Hao Jing
Editor: Kou Jianchao
This article is reprinted with permission from academic headlines (ID: SciTouTiao), the original title is "The real smart wear! The University of California makes a new type of fabric, a stroke of the sleeve can be safely paid, but also can monitor health, if you need to reprint for the second time, please contact the original author.