An Exoskeleton glove which enhances and supports the movement of the human palm
The aim of the project is to invent a metallic exoskeleton glove that assists, supports and enhances the movement of the human palm, in order to help people who suffer from upper hand disabilities.
The main idea of the project is that a metallic exoskeleton will be worn by the user as a glove and having placed in the right spots pressure sensors, it will be able to detect the kinetic stimulus of the user which then will be amplified with the use of servo motors.
Many humans have the misfortune of not having the ability to use their limbs. This makes it difficult to impossible to use everyday devices. In order to help solve either congenital or acquired disabilities, and at the same time discover an innovative technology, the focus of this project is with people experiencing upper limb disabilities, namely those showing weak movement of the palm/fingers. These people either move their limbs slightly, or do not have the stability to move and grab everyday objects. This topic was chosen because one day I realized how difficult my grandmother's everyday life was, by suffering from an upper hand disability that she has not the proper amount of grasping force to use every day objects and devices.
In order to solve such a problem, I invention after two and a half years, an exoskeleton glove, that can sense the human's palm kinetic stimulus with the help of pressure sensors, a processing system which runs a simple algorithm based that drives some powerful precision motor mechanisms, in order to enhance and support the user's force in real time.
As my invention performs in the way that was designed to do, my future plans are, to start a online campaign in order to attract the interest from businesses and manufacturers around the world in order to, my device to be affordable for any people who needs it worldwide.
My name is Charalampos Ioannou, I am 17 years old and I live in Athens, Greece. I am a senior student in high school and I want to study Electrical Engineering.I do mountain biking and for the last six years, I have worked as a D.J in order to obtain the proper funds that my projects demand.Ever since I was a child, I have always been curious about how things function, therefore every toy I had, was taken apart. At the age of 9, I had already started building my own workshop, with my own resources, where I am able to develop my projects.
During the past years, since my country's education system has not neither programming nor other subjects related to engineering in its curriculum, and my family environment was not able to provide me this kind of knowledge, I started watching online lectures from universities. This gave me the opportunity to gain further knowledge in the fields which I'm interested in, such as, programming robots, computer vision, open source software and other. I presented the current project in TEDx Athens, as the youngest speaker, last November.
Wining Google Science Fair Competition will encourage me to continue develop projects that will make people’s lives easier and better. Moreover the money of the price and the recognition, will be a huge boost for my career but most importantly they will help me to promote, finalize and mass produce my project, in order to help people around the world.
One day I saw my grandmother trying to grasp the television's remote control and it was sliding from her fingers, since she suffers from an chronic upper hand disability. This stimulated me, to sit and wonder whether I could make a device in order to help her. After doing some research I found out that was not any device that its intended neither for everyday use, nor in rehabilitation centers. Thereby I asked myself what is finally the aim of technology if it is unable to solve such a basic problem. When it comes to a health problem either a millionaire or one at risk of poverty, whether black or white, young or old the problem remains the same. Taking into consideration that almost 85% of the devices used for everyday needs require at least the use of one or two hands, I deduced that such a device was crucial. Therefore I envisioned a device that would solve the problem of failures due to lack of power to the fingers of the hand, in the best possible way.
I started my research from rehabilitations centers around the globe in order to find if devices like the one that I wanted to make were already been made before and I did not find anything, that is why I expanded furthermore my research in the industrial field and scientific publications, where I found two devices that seem to be similar to what I wanted to make. Those are:
A) Laboratoire de Robotique de Paris (LRP) Dextrous Hand Master (DHM)
The robotics department of the university of Paris, has made a dexterous hand called in sort (DHM). It is in considered from a cloth glove which on it they have placed miniature force sensor on each phalanx so as to measure the force of the user. In order to apply forces on each phalanx of the hand it uses tendons. Each one of the 14 joints, is actuated through a tendon-sheath transmission by DC, disk motors, placed remotely from the hand. Thus it is very heavy, very bulkiness and expensive. Facts that make this device far from the needs of the market.
On the other hand, NASA followed a slightly different path:
B) NASA (National Aeronautics and Space Administration) Human Grasp Assist device (K-Glove, Robo-Glove)
In contribution with General Motors, NASA created a robotic cloth glove for humans that can reduce repetitive stress injuries by assist assembly workers, astronauts and others who need to grip and release objects repeatedly. Their device can only assist one movement per finger. It is only intended workers thus it is not very sensitive and stable, making it in this way inappropriate for handling fragile and delicate everyday objects.
By taking into consideration, the already made machines, I concluded that the field of a device that will assist and enhance the strength of the human palm was not covered at a level that will help people around the world who are unable to do everyday tasks.
As my grandmother can move her fingers but she has not the proper amount of power to grasp objects, the current device is addressed for people who can move even slightly their fingers.
Motion detection is achieved with the help of pressure sensors called FSR (Force sensing resistors) because they are made of a polymer material, which according to the external force applied on them alter their internal resistance
The analog signal from each sensor is directed to the 1st electronic circuit or Prototype Circuit Board (PCB) which I have designed and build in my workshop. The signals undergo a process of voltage division in order to be calibrated. The PCB also decreases the volume of cables, because the ten separate analog signals exit the board via one scart cable. Scart is used because of its low weight and high cable density.
By using ten (1 for each movement) programmable microprocessors (Atmel's AVR Tiny85) the analog signals from the 1st PCB are converted into digital. As seen in figure above, each microprocessor is supplied with and analog input, from the input scart cable (orange wires) and after it is converted into digital via the yellow wires, is connected to the output scart cable. The red and black wires are connected in parallel with the 5V external power supply. The board has designed and programmed only by me with the help of an open source software called arduino.
The digital signals from the processing board enter the third PCB via the output scart cable, which then are splitted in order to control the precision motor mechanisms which are called servo motors and have the ability to control very precisely with an embedded feedback mechanism their circular movements varying from 0 to180 degrees. These movements are controlled by deviating from the microprocessors the time that the digital signal is on and off and it's called PWM (Pulse Width Modulation)
Lastly, I constructed a metallic glove which has the same degrees of freedom as the human palm, in this way it does not alter any of its physical movements. It has to be constructed from a material such that all external forces act on the glove and not on the patient’s palm that's why it is called exoskeleton, but due to lack of fundings and technical knowledge, I chose to construct it from hard copper wire, which is relatively cheap, easy to handle and it can be bend into complex shapes. On the exoskeleton glove we place the sensors in the end and at the middle of each finger and the servo motors, in such way that each motor can provide mobility for each finger separately. To simplify the layout, the programming and reduce the weight, instead of using 15 servomotors, I used 10, since each phalanx does not move completely independent from the others. Furthermore the first and the third board were installed on the glove, while the second is kept off the exoskeleton for weight reduction.
In conclusion, we have built an electro-mechanical device which the user wears like a normal glove and has the ability since it measures the kinetic stimulus from the user even the slightest ones, it process it with the help of programmable microprocessors and according to the algorithm used and the received data, it moves the proper servo motors which they move successively each phalanx of the glove and the user in real time, enhancing and assisting in this way the movement of the human palm.
After wearing the device for several hours for three months for testing, I figured out that the constructed glove mechanism it is crucial to fit almost perfectly onto the user’s hand, and does not alter any of its physical movements, facts that my exoskeleton had in great rate but was quite heavy.
The processing system despite the fact that it is considered from three boards, fact that could cause external errors and system failures, it performed really well. In the same way the servo motors provided a great amount of force but sometimes were getting hot.
The sensors proved that they had a great amount of error in their receiving values and this caused the debugging procedure very timing consuming and difficult.
The device in numbers:
• 30m of copper wire was used for the exoskeleton glove
• 17m of cables for wiring of the circuits
• 10 pressure sensors
• 10 Servomotors
• 10 programmable microprocessors model: Atmel Attiny85
• 3 signal analysis PCBs
• 22 months of construction
• Cost: 380 €
The pressure sensors which I have placed on the exoskeleton glove are receiving a quite reliable range of values but due to their 10% of error that they produce and if you consider that the human force is the hardest detected force, this is a topic that in the next version of the device is going to be under serious consideration, because during use of the glove it produces instability to the motors .
The processing algorithm performs very good despite the error that the sensors have and the reaction time is very little about 10 microseconds so in later versions the processing algorithm won't change remarkably. Moreover the servo motors are to be replaced by new ones that they will be much lighter and they will provide about 15 kg force per finger.
The metallic glove despite the fact that its constructed from relatively heavy material its weight does not exceed 350 grams, in this way its easily wearable and very easy to use. The exoskeleton will be redesigned in an Computer Aided Design program I order to make it smaller, cheaper and by performing stress analysis in finite element analysis, we will achieve a very lighter and durable glove. In addition, in order to mass produce the exoskeleton glove and to meet the needs of every single customer the exoskeleton glove will be 3d printed in a combination of ABS and PLA plastics and from powdered aluminum and titanium metals, reaching in this way the risibility and the flexibility that the glove has to offer.
As we see this mechanical glove does not only apply in situations with human disability, but also in the case of exerting larger forces by users need or want to enhance the force exerted by their palm. This is why the basic difference of this devise from all the others is that it can enhance the strength in any level we want as all the external forces carried on the exoskeleton glove that can be constructed from very durable metals.
I would like to thank my family, friends and school for the encouragement and the mental support who gave me during construction. I have also to thank Dr. Pericles Bakogiorgos my physics teacher, for helping me with the documentation of the project. I did not use any facilities except of mine small workshop in the garage of my house and the tools used were a personal computer for programming, a soldering iron, cut pliers, wires etc, so I did not used any specialized equipment.
References and biography
The currently device is totally unique worldwide because it is considered as an invention with reference number: 20120100139, thus the references are related only with its subsystems, sensors, programming the microprocessors, servo motors, constructing and designing the prototype circuit boards. Moreover because all the theoretical and practical knowledge that was needed for this project was not included in the school curriculum and I did not have anyone either to answer my questions nor help me in the design process and construction, thus all the information was gained from online university lectures, open source software and hardware.
Images and resources:
Software and programming:
Online lectures and tutorials:
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