Tag Archives: wearable

Bosch BMA400 – Did you thought accelerometers couldn’t get any better?

Accelerometers are used in almost all fields, and they have been growing in popularity in IoT and wearables. Nowadays, those devices require a of energy, and because of this, they need to be constantly charged or batteries need to be constantly changed which causes users to lose interest, or to be limited by this problem. Size might be a problem too because some MEMs (micromechanical systems) acceleration sensors are too big to be implemented in everyday portable objects. In June 2018, Bosch will unveil their BMA400, a sensor that extends battery life and has a huge range of capabilities in a small size.

BMA400 is capable of measuring tilt, orientation, tap/double tap, and step counting (with activity recognition) using a low- noise measurement of accelerations in three perpendicular axes. Additionally, the device only uses 10% of the energy current comparable devices use which makes it useful for applications where charging is impossible. For example, this device could be used for package tracking over long distances, saving power by putting itself on sleep mode until something happens (the package is mishandled) which could compromise the quality of the product inside the package.

Other applications include home automation (automatic air conditioning that considers status (open or closed) of windows and doors), security (burglar detection), and sports. The BMA400 includes an activity detection function that can differentiate between walking, running, and standing. All this could be applied into wearables, and because of its size it could be a game changer in hybrid smartwatches (traditional watch with added smarts in a discrete way).

BMA400 measure only 2 mm x 2 mm x 0.95 mm, and device data can be retrieved over longer intervals (FIFO buffer of 1kB). Other specifications include:

  • 12-bit digital resolution
  • Output data rate (ODR) of 12.5 Hz to 800 Hz
  • Supply voltage of 1.71 V up to 3.6 V

Complete list of specifications can be found in the official website.

This improvements in an already widely used technology could result in advances in thousands of different devices, and in the implementation of this sensor in devices where it couldn’t be fitted before. Improving battery means improving product usability which results in happy users who can now use their device for longer periods of time. Also, makers and hobbyists could now apply this technology to new devices using the increased battery life as an advantage.



Intexar™ Heat – A Revolutionary Stretchable Ink And Film Technology To Make Flexible Heated Garments

DuPont Advanced Materials (DuPont) in association with Taiwanese company Formosa Taffeta, has developed a powered smart clothing technology named Intexar™ Heat, for on-body flexible heating garments.

The new fabric is thin, lightweight, and durable. The Intexar™ Heat is an ideal solution for outdoor clothing and it is designed to be easily integrated into garments. This innovative technology consists of a thin layer of carbon resistors, interconnected by an underlying layer of silver electrodes printed on a stretchable thermoplastic polyurethane (TPU) laminate. The silver electrodes supply currents throughout the resistor grid to radiate a right amount of heat within garments. By default, the active layer is sandwiched between a plain or customized outer protective layer. This protective layer shields the heating element from exposure and the fabric making up the garment.

Intexar Heat powers smart clothing technology for on-body heating
Intexar Heat powers smart clothing technology for on-body heating

Michael Burrows, the global business manager at DuPont Advanced Materials, described Intexar™ Heat as a revolutionary stretchable ink and film that when powered, creates a comfortable warmth. Formosa Taffeta Company will be the first textile manufacturer to apply Intexar™ Heat technology as part of its Permawarm® line. The new Permawarm® lineup will provide clothing with a complete garment heater system including the Intexar™ heater layer, connectors, and control software.

James Lee, president of FTC, said,

With Permawarm™, clothing brands can focus on garment design and brand engagement. We are taking the guesswork out of bringing their customers safe and comfortable heated garments.

Intexar™ materials can also be very useful in biometric monitoring in smart clothing. Pulse rate, respiratory rate, muscle activity and form awareness are all measurable using sensors and conductive pathways built from Intexar™ which makes it a complete smart garment solution.

To cope with the coming era of functional thermal insulation this is a huge step forward for heat-insulation fabrics. It is a new high-tech lightweight material ideal for thermal insulation in the winter.

World´s Smallest Wearable Made to Help Prevent Skin Cancer

Wearables are devices that incorporate and interact with different parts of our bodies and perform a specific task. The tasks can be to improve our health (count steps, heart rate etc.) or to make our life easier (GPS, smartwatches etc.). Technology industry has dominated the wearable market since its easier for a technology company to produce technologic devices, but other companies have joined the trend and now companies in the textile, fashion and medical industry started producing their own wearables with specific purposes. L’Oréal the world leader on makeup, cosmetics skin care etc. has now joined the race.

In a research project with Northwestern university, the world´s smallest wearable was created. Measuring less than an M&M in circumference and weighting less than a raindrop this device was designed to measure UV exposure of the user to reduce skin cancer by modulating their exposure to the sun. UV Sense has no battery, no moving parts, its waterproof, and it can be attached to any part of the body preferably a location with good sun exposure.

The device connects to an app that shows you the exposure you have had in a day or over a period. Also, the app can be configured to send notifications when users exceed daily safe sun limit.

According to the skin cancer foundation “Each year in the U.S over 5.4 million cases of nonmelanoma skin cancer are treated in more than 3 million people, and each year there are more new cases of skin cancer”, but with this device skin cancer could be prevented instead of treated. The researchers at Northwestern have received roughly 2 million grant from the National institutes of Health to deploy fingernail UV sensors.

The device is undetectable which will encourage people to use it, and as it requires no batteries, users do not need to worry about charging the device or forgetting to do so. This means that people can now be warned about sun exposure and will be able to take measures to prevent diseases with no effort at all. The same research team is also working on other devices that could help check other health aspects to increase awareness about different diseases and the daily activities that may cause them.


Researchers Develop Transparent Flexible Terahertz Sensors With Graphene

The researchers of the Swedish Chalmers University of Technology have developed a new design of terahertz sensor using Graphene. This flexible sensor can be integrated into wearable materials. Most importantly, it can be manufactured very cheaply and also it is practically transparent. This new type of sensor could be a major breakthrough by opening doors of many new applications.

Flexible Graphene sensor by Chalmers University
Flexible Graphene sensor by Chalmers University

The terahertz frequency band ranges from 100 to 10,000 GHz. Terahertz radiation is able to penetrate materials that block visible and mid-infrared light. This technology opened up a range of potential applications in medical diagnostics, process control, and even intelligent vehicles. Jan Stake, the head of the Terahertz and Millimetre Wave Laboratory at Chalmers, said,

Terahertz graphene-based FET detectors have been demonstrated on rigid substrates such as SiO2/Silicon, and flexible devices such as graphene and other concepts have been demonstrated at RF/microwave frequencies.

This band is also used by the so-called “nude-scanners” used at airport check-in desks to look for illegal items carried by passengers. THz waves penetrate normal clothing hence it can detect weapons made of plastic. As Non-metallic weapons cannot be detected by ordinary metal detectors used at the entry gates and by hand-held scanners. Thus these new inexpensive sensors can enhance security for everyone.

Terahertz transmissions have enormous bandwidth available. THz signals can be used as carriers for high-speed information links over short distances allowing data speeds up to 100 Gb/s. On the other hand, THz waves allow uninterrupted visibility in fog or rain for motorized vehicles.

There are many medical applications of the technology using sensors that are cheap to produce and are physically small. One important example is in the field of dermatology. Skin regions affected by cancer have a different reflective index to THz waves which makes the sensor a useful diagnostic tool.

Although being under development for a long time, conventional THz sensors were always large and expensive. With this new design, the Swedish research team has enabled the tech world with mass production of the sensors. New sensors will be small, flexible and cost-effective. Development of the sensors was funded by the European Union under the Graphene Flagship Initiative.

What the Chalmers team has done to combine flexibility and terahertz detection could also make it possible to build an Internet of Things connected via high-bandwidth 5G technologies.

Researchers Develop New Technique To Print Flexible Self-healing Circuits For Wearable Devices

The researchers of North Carolina State University in the US, lead by Jingyan Dong, have developed a new technique for directly printing flexible, stretchable metal circuits. The innovative technique can be used with multiple metals and alloys. It is also compatible with existing manufacturing systems which can integrate this new printing technology effortlessly.

Flexible PCB designed by the researchers
Flexible PCB designed by the researchers

The technique uses the well known electrohydrodynamic printing technology. This popular technology is already used in many manufacturing processes that use functional inks. But instead of using conventional functional ink, Jingyan Dong’s team uses molten alloys having melting point as low as 60 degrees Celsius. This new technique was demonstrated using three different alloys, printing on different substrates such as glass, paper, and two types of stretchable polymers. Jingyan Dong added,

Our approach should reduce cost and offer an efficient means of producing circuits with high resolution, making them viable for integrating into commercial devices.

The researchers tested the flexibility of the circuits on a polymer substrate and found that the circuit’s conductivity was uninterrupted even after being flexed 1,000 times. The circuits were still electrically firm even when stretched to 70 percent of tensile strain. The above figures are surprising enough, especially when printing flexible wearables is the main target.

Even more interesting, the circuits can heal themselves if they are broken by being bent or stretched beyond their limitations. On the other hand, because of the low melting point, one can simply heat the affected area up to around 70 degrees Celsius and make the metal flow back together, repairing the related damage with ease.

The researchers demonstrated the functionality of the printing technique by creating a high-density touch sensor, packing a 400-pixel assemblage into one square centimeter. The researchers have demonstrated the flexibility and functionality of their approach. Now, they are planning to work with the industry sector to implement the technique in manufacturing wearable sensors or other electronic devices.

The days of truly flexible, self-healing wearable smart gadgets are not so far because of the hard work of these researchers.

Biosensors with ECG function for heart rate monitoring in wearables

Graham Prophet @ eedesignnewseurope.com writes:

Silicon Labs has introduced a family of optical biometric sensors providing advanced heart rate monitoring (HRM) by transcutaneous optical measurements, along with electrocardiogram (ECG) capabilities, for a range of wearable fitness and wellness products.

Si117x sensor modules combine ultra-low power, high sensitivity and integration, for smart watches and wrist-based, patch-type and other wearables requiring long battery life and enhanced HRM accuracy. To simplify development and speed time to market, Silicon Labs offers a complete, end-to-end sensing solution featuring the Si117x sensor module, HRM algorithm, Wireless Gecko SoCs for Bluetooth connectivity, and a wrist-based development kit with sample code and example projects.

Biosensors with ECG function for heart rate monitoring in wearables – [Link]

Researchers Developed New Efficient, Thin, and Flexible Cooling Device

Engineers and scientists from the UCLA Henry Samueli School of Engineering and Applied Science and SRI International, California, have created a thin flexible device that could keep smartphones and laptop computers cool and prevent overheating. The component is based on the electrocaloric effect – a phenomenon where the temperature of material changes when an electric field is applied to it. The research has been published in Science.

Thin, flexible cooling device
Thin, flexible cooling device

The system’s flexibility also allows it to be used in wearable electronics, robotic systems, and new types of personalized cooling systems. It is the first demonstration of a solid-state cooling device based on the electrocaloric effect. The method devised by UCLA and SRI researchers is very energy-efficient. It uses a thin polymer film that transfers heat from the heat source – a battery or a processor – to a heat sink, and alternates contact between the two by switching on and off the electric voltage.

Because the polymer film is very flexible, the system can be used in devices with complex shapes or moving surfaces. Body tracking wearable devices can easily accommodate this flexible cooling device. Such cooling pad could keep a person comfortable in a hot office and thus lower the electricity consumption for air conditioning. Or it could be placed in a shoe to keep a runner comfortable while running in the sun. It’s like a personal air conditioner.

The tendency of flexible electronics to overheat remains a major challenge for engineers. The cooling systems in larger devices like air conditioners and refrigerators, which use vapor compression, are just too large for mobile electronics. The new cooling device produces a specific cooling power of 2.8 watts per gram and a COP of 13. This is more efficient and compact than the existing surface-mountable solid-state cooling technologies, opening a path to using the technology for a variety of practical applications.

Roy Kornbluh, an SRI research engineer, said,

The development of practical efficient cooling systems that do not use chemical coolants that are potent greenhouse gases is becoming even more important as developing nations increase their use of air conditioning.

Researchers Developed Hybrid 3D Printing Method To Make Flexible Wearable Devices

Wearable electronic devices that intend to track and measure the body’s movements must be soft enough to flex and stretch to accommodate every body-movement. But, integrating rigid electronics on skin-like flexible materials has proven to be challenging. Clearly, Such components cannot stretch like soft materials can, and this mismatch frequently causes wearable devices to fail. Recently scientists solved this problem by developing a new method called hybrid 3D printing.

Making wearble devices using Hybrid 3D Printing method
Making wearable devices using Hybrid 3D Printing method

A collaboration between the Wyss Institute, Harvard’s John A. Paulson School of Engineering and Applied Sciences, and the Air Force Research Laboratory, has resulted in developing hybrid 3D printing method. It combines soft, electrically conductive inks, and matrix materials with rigid electronics into a uniformly stretchable device. Alex Valentine, a Staff Engineer at the Wyss Institute says,

With this technique, we can print the electronic sensor directly onto the material, digitally pick-and-place electronic components, and print the conductive interconnects that complete the electronic circuitry required to ‘read’ the sensor’s data signal in one fell swoop.

To make the circuits and the flexible layers, the researchers use thermoplastic polyurethane (TPU), both pure and with silver flakes. The method is quite easy to understand. As both the substrate and the electrodes contain TPU, they firmly adhere to one another while they are co-printed layer-by-layer. After the solvent evaporates completely, both of the inks harden, forming an integrated system that is both flexible and stretchable.

As the ink and substrate are 3D-printed, the scientists have complete control over where and how the conductive features are patterned. Thus they can design circuits to create soft electronic devices of nearly every size and shape. The hybrid 3D printing method enables development of flexible, durable wearable devices that move with the body.

A ring that is made using flexible conductingmaterial
A ring that is made using flexible conducting materials

Conductive materials exhibit changes in their electrical conductivity when stretched. Soft sensors, that detect movements, are made of those materials and are coupled with a programmable microcontroller to process those data. The microcontroller also transmits the data to communicate in a human-understandable way. As a proof-of-concept, the team created two devices – a wearable device that indicates how much the wearer’s arm is bending and a pressure sensor in the shape of a person’s left foot.

Watch the video to know about them,

Alzheimer’s Wearable Assistant

A smartwatch with fall and location detection, reminders and more, designed to help you or your loved one with Alzheimer’s!

When I saw Infineon’s Sensor Hub Nano, it appeared to be a good candidate in such a project, because of its very small size and BLE capabilities. With the accurate pressure sensing, it could be used to detect if the patient has fallen and also tell where exactly the patient is in the house.

Alzheimer’s Wearable Assistant – [Link]

A multi-protocol SoC for ultra low-power wireless applications

Author: Maurizio Di Paolo Emilio

The nRF52840 SoC of Nordic Semiconductor is based on a 32-bit ARM Cortex-M4F CPU running at 64 MHz with flash and RAM integrated on chip. Ultra low-power wireless applications can use this advanced multi-protocol SoC with different communication protocols.  The 2.4 GHz transceiver supports Bluetooth low energy (Bluetooth 5), 802.15.4, ANT and proprietary protocols. The transceiver also supports high resolution RSSI measurement and automated processes to reduce CPU load. Moreover, EasyDMA for direct data memory access and packet assembly provides full support for hardware (figure 1). The device maintains the compatibility with existing products such as nRF52, nRF51 and nRF24 series.

ultra low-power wireless applications
Figure 1: Block diagram of the nRF52840 SoC

Bluetooth 5 and SoC

Bluetooth 5 (500kbs e 125kbs) is the latest version of the well-known wireless technology. It increases the range of four times and the throughput of eight times, making this technology much more suitable for ultra low-power wireless applications such as wearable, Smart Home and more generally for Internet-related applications (IoT, IIoT). The ultra low power consumption of the Bluetooth 5 protocol facilitates high performance, advertising extension and modulation schemes.

nRF52840 SoC uses power management resources to maximize job processes and achieve an optimal energy efficiency. The power supply ranges between 1.7V and 5.5V ensures a wide choice of batteries. In addition, SoC can also work with USB direct power supply without external regulators. Especially relevant, all devices have automatic clock management with adaptive features to maintain minimal power consumption.


  • multi-protocol SoC
  • 32-bit ARM Cortex-M4F Processor
  • 1.7v to 5.5v operation
  • 1MB flash + 256kB RAM
  • Bluetooth 5 support for long range and high throughput
  • 802.15.4 radio support
  • On-chip NFC
  • PPI –Programmable Peripheral Interconnect
  • Automated power management system with automatic power management of each peripheral
  • Configurable I/O mapping for analog and digital I/O
  • 48 x GPIO
  • 1 x QSPI
  • 4 x Master/Slave SPI
  • 2 x Two-wire interface (I²C)
  • I²S interface
  • 2 x UART
  • 4 x PWM
  • USB 2.0 controller
  • ARM TrustZone CryptoCell-310 Cryptographic and security module
  • AES 128-bit ECB/CCM/AAR hardware accelerator
  • Digital microphone interface (PDM)
  • Quadrature decoder
  • 12-bit ADC
  • Low power comparator
  • On-chip 50Ω balun
  • On-air compatible with nRF52, nRF51 and nRF24 Series

Development kit

The NRF52840-PDK is a versatile development kit based on nRF52840 SoC for the development of projects by using Bluetooth Low Energy, ANT, 802.15.4, and proprietary 2.4GHz protocols. Moreover, It is also hardware-compatible with the Arduino Uno R3 standard, allowing to use third-party compatible shields. Adding an NFC antenna, the kit enables the NFC tag feature (figure 2 and 3).

ultra low-power wireless applications
Figure 2: NRF52840-PDK development kit


ultra low-power wireless applications
Figure 3: block diagram of the NRF52840-PDK development kit