Biobattery-embedded tattoos to use sweat to power your tech

Scientists have developed a temporary tattoo with a built-in, sweat-powered biobattery that could one day be used to charge your phone while you are out for a run.

The biobattery works using lactate, a key chemical found in sweat that can be used to monitor exercise performance.

This means that the more the wearer sweats, the more energy is going to be produced, creating the interesting scenario where less physically fit people are able to produce more power.

The technology is one of the first examples of skin-based power sources, and could pave the way for a host of technologies powered by devices attached to the skin.


The biobattery works by using an enzyme to extract the electrons in the sweat’s lactate and move them to the battery. At present, the amount of energy produced is very small, but the researchers are confident that they will be able to develop this to enable small electronic devices to be charged.

“The current produced is not that high, but we are working on enhancing it so that eventually we could power some small electronic devices,” said Dr Wenzhao Jia, a postdoctoral researcher at the University of California San Diego.

“Right now, we can get a maximum of 70 microWatts per cm², but our electrodes are only 2 by 3 millimeters in size and generate about 4 microWatts — a bit small to generate enough power to run a watch, for example, which requires at least 10 microWatts.

“So besides working to get higher power, we also need to leverage electronics to store the generated current and make it sufficient for these requirements.”

The device has also been developed as a lactate monitor, which will be a valuable tool for both doctors and athletes. Previously lactate has been monitored using a series of blood tests, so this monitor is likely to prove simpler and less invasive.

The biobattery’s reliance on sweat means that the amount of power produced can vary significantly depending on the person wearing it.

The researchers tested the initial biobattery on 15 exercise bike-riding volunteers, and found that not only did those who were least fit produce the most energy, but the most regularly active participants produced the least energy.

This could affect the potential success of the technology, as such variation in performance could make it difficult to market.

However, this is one of the first examples of skin-based batteries, and the technology is likely to be developed much further.

“These represent the first examples of epidermal electrochemical biosensing and biofuel cells that could potentially be used for a wide range of future applications,” said Dr Joseph Wang, professor of nanoengineering at University of California San Diego.

From here we could see the development of an array of wearable technologies and gadgets siphoning power through our skin, perhaps even one day powering whole computers, medical augmentations and more.

Inline image courtesy of Dr Joseph Wang.

It may be up to 15 years before we create a robotic hand that is able to perform as well as a human hand. However, NASA has been making great strides in development of robotic limbs. We look at its secrets behind a robot's finger

Designing and creating robots is not a simple job, and creating one that can be used on another planet comes with even more challenges.

However, NASA has revealed detailed designs behind one of the crucial components to creating its human-like space robots.

In a patent, which was recently published on NASA’s website, the space organisation details the complex construction of a robot’s finger.

The sixteen-page patent, which has been fully released, details how the joints of the finger are put together and interact with the robotic elbow, shoulder and more.

robonaut3While the robot displayed in the patent isn’t described as Robonaut, it bears a large resemblance to the humanoid robot that is currently in space. It is possible the patent relates to Robonaut.

One version of the robot (R2) is already in space, and the development of future versions will be important to the success of future space missions.

In total NASA applied for 46 patents for the technology in R2, 21 of which were related to the hand.

Creating a robotic hand that is capable of completing human-like movements is one of the most complex areas of robotics, and the NASA patent sheds some light on the process, as well as the way that it thinks of humanoid robots.

Humanising the robot

In essence for the robot to count as a humanoid it needs to be recognisable as being designed to have a human appearance or traits.

The patent describes humanoid robots as having ”approximately human structure or appearance” and states that this can be a full body, a torso and the structural complexity of the robot being based upon the nature of the task that it is created for.

“The use of humanoid robots may be preferred where direct interaction is required with devices or systems that are specifically made for human use,” the patent reads.

“Due to the wide spectrum of work tasks that may be expected of a humanoid robot, different control modes may be simultaneously required.

“For example, precise control must be applied within the different spaces noted above, as well as control over the applied torque or force, motion, and the various grasp types.”

robonaut2The benefits of having a humanoid robot in space come from its ability to complete the same tasks as its astronaut companions. For example, once the technology has been perfected, it is possible a humanoid robot in space could complete lengthy repairs to the exterior of a spacecraft – which would not be possible due to the oxygen that would be needed for an astronaut to undertake the work.

Repairs of this nature, or any general work, are likely to involve basic human actions, such as twisting, griping, and lifting.

Therefore it makes sense to build a robot that we are able to control in a similar way to how our own bodies work. In some of its most recent developments, NASA has been training Robonaut to perform surgery.

As we look toward the stars in search of putting humans on another planet, and in the further future the colonisation of those planets, robots that are able to aid astronauts in their daily activities will become more important as an aid to space exploration.

Building the hand

Creating a robotic hand that is able to imitate the human equivalent is a task that is riddled with difficulty.

Our hands, thanks to 27 individual bones, are capable of delicate and intricate movements in a range of different directions. Replicating this is in a robotic creation requires skilled engineering.

“A human hand is incredibly complete, which makes it a challenge to try to put all of the necessary pieces into the robotic hand and to integrate all of the actuators that allow for mobility similar to that of a human hand,” said Professor Mohamed Abderrahim from Universidad Carlos III de Madrid.

Abderrahim is helping to develop robotic hands that can be used in the future. He foresees that a robotic hand that can effectively mimic the abilities of a human hand.

NASA’s patent shows there are hundreds of parts to the robotic hand and fingers.

This hand is, naturally, connected to the overall arm of the robot, which comprises of a shoulder joint assembly, upper arm, forearm and elbow joint. The symmetrical structure on both the left and right sides is intended to be identical.

The hand has been designed, as much as possible, to be the same as a human hand. “A robotic hand assembly includes a base structure; a finger having first, second, and third phalanges,” the patent says.

It therefore follows that the size of the hand has also been modelled on that of humans. NASA says that it is comparable in size to that of “a sixtieth to eight-fifth percentile human male hand”.

In reality the hand that it depect is is 7.9in (20cm) long with a width of 3.6in (9cm).

Each finger is split into three different phalanges, in the same way human fingers are, which all have different capabilities.


All images courtesy of NASA.

Describing how a single finger works, the patent says: “a first joint operatively connecting the first phalange to the base structure such that the first phalange is selectively rotatable with respect to the base structure about a first axis.

“A second joint operatively connecting the second phalange to the first phalange such that the second phalange is selectively rotatable with respect to the first phalange about a second axis; and a third joint operatively connecting the third phalange to the second phalange such that the third phalange is selectively rotatable with respect to the second phalange about a third axis.”

This set-up allowed for a greater level of dexterity than was expected, and has seen the hand also incorporate sensors, actuators and tendons, which can be compared to the nerves, muscles and tendons that can be found in the human hand.

At the end of its fingers are touch sensors and each finger has a grasping force of 5lbs.

Developing the robotic hand

The success of Robonaut and its hands has meant that the technology behind it has also been used to create robotic gloves for human use.

General Motors and NASA used Robonaut’s tech to develop a Human Grasp Assist device, known as the Robo-Glove, to help astronauts and industry workers to easily complete the jobs they are tasked with.

The thoughts behind this include helping workers apply additional force to tasks – a valuable ability in manual work – and is expected to reduce the risk of repetitive strain injury.

Whatever the timescale on the development of robotic hands is, getting a hand to work in a natural human-like manner is becoming more of a reality.

NASA will continue to stretch what is possible and this will then filter down to commercial applications in everyday use.

When the robotic hand is perfected it will allow humans, on Earth and beyond, to take a more hands-off approach.

Planes don’t carry missiles in DARPA’s “new concept for air warfare”

DARPA is working on a new “concept for air warfare” that involves drones communicating with a fighter plane and a larger airship.

In a new video posted on its website, the US defence research agency proposes a plane being able to communicate directly with weapons, sensors and other mission systems.

The video shows the plane sending data to a series of drones that are ahead of its flight-path and then using the information it receives to launch an attack from a second plane, which is further back.

Nanoneedles show promise for organ repair after growing new blood vessels in mice

Minuscule nanoneedles that can initiate the growth of new blood vessels have successfully been demonstrated in mice, prompting hopes for their use in humans.

Developed by scientists from Imperial College London and Houston Methodist Research Institute, the nanoneedles are designed to deliver nucleic acids – the building blocks of living organisms – that encourage blood vessels to generate.

However, the scientists believe that in humans the nanoneedles could be used to generate far more than just blood vessels.

They also see the nanoneedles being used to repair damaged organs and nerves, and to improve the success rate of organ transplants.

“If we can harness the power of nucleic acids and prompt them to carry out specific tasks, it will give us a way to regenerate lost function. Perhaps in the future it may be possible for doctors to apply flexible bandages to severely burnt skin to reprogram the cells to heal that injury with functional tissue instead of forming a scar,” explained Dr Ciro Chiappini, study first author and member of Imperial College London’s Department of Materials.

“Alternatively, we may see surgeons first applying the nanoneedle bandages inside the affected region to promote the healthy integration of these new organs and implants in the body.”


An image taken using optical microscopy showing human cells (in green) injected with DNA (in blue) on the (orange) nanoneedles.

The nanoneedles work over other approaches because they are porous, enabling them to more effectively deliver nucleic acids than tools which are solid, and can penetrate cells without damaging them, a remarkable step in targeted treatments.

“This is a quantum leap compared to existing technologies for the delivery of genetic material to cells and tissues,” said Ennio Tasciotti, study co-author and co-chair of the Department of Nanomedicine at Houston Methodist Research Institute.

“By gaining direct access to the cytoplasm of the cell we have achieved genetic reprogramming at an incredible high efficiency.”

This also has the benefit of enabling bespoke treatments designed to work with specific patients, something that is increasingly been pursued to improve healthcare.

“This will let us personalise treatments for each patient, giving us endless possibilities in sensing, diagnosis and therapy. And all of this thanks to tiny structures that are up to 1,000 times smaller than a human hair,” added Tasciotti.

Finally, the nanoneedles are made of a biodegradable silicon that degrades within a few days. As a result, they can be left in the body after insertion, reducing costs and patient stress associated with their use.


A colourised electron microscopy image showing a human cell (brown) on the nanoneedles. Images courtesy of Imperial College London

While the technology shows potential, there is a long road ahead before the technology can be used in humans.

“It is still very early days in our research, but we are pleased that the nanoneedles have been successful in this trial in mice,” said Professor Molly Stevens, study co-author and member of Imperial College London’s Departments of Materials and Bioengineering.

“There are a number of hurdles to overcome and we haven’t yet trialled the nanoneedles in humans, but we think they have enormous potential for helping the body to repair itself.”

For now, the scientists are developing a flexible bandage that could be used both on and inside the body to enable treatment to be targeted.

The research was published today in the journal Nature Materials.