A tactile didactic tool based on vibration for children with combined hearing and vision loss

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The Loono didactic tool is focused on the development of tactile perception for children with combined hearing and vision loss, acting at the same time as a relaxing object and an educational tool.
It intends to stimulate the brain via vibrations and thus develop tactile-haptic perception and proprioception (the ability to coordinate body in space).
The user concentrates on the search for similar vibrations, by which the tactile sensors are simultaneously activated, since touch is one of the most important senses for deaf-blind individuals.


People with combined hearing and vision loss lack significant sensory information when interacting with the world. They have to develop their sense of touch extraordinarily in order to compensate. They cannot read and have to learn Braille.

But how do children learn how to develop and perfect touch? Currently, there exist only a few toys for blind and deaf children, but none of them actually guides the child in a learning and development process.

Loono aims at solving this issue by providing a device that helps children to discover and enhance their sense of touch and guides them along a learning process in order to get better and better.

The device and its goal

Loono consists in a four pebbles, each separated in two halves. The principle of the game is similar to "pairs" or "memory", based on perception of different or similar vibrations.

The child must first concentrate on finding a pair of wooden parts with the same vibration. Once the right pair of stones (i.e. with the same vibration) is found and connected, they begin to vibrate with ‘winning’ tune, which is a reward for the child and confirmation of the correct choice. If non-matching stones are connected, they will cease to vibrate, which is a feedback for the child about the incorrect choice.

By connecting two matching halves an integral object is formed, representing a relaxing object that changes its vibration to a soothing phase with prolonged vibration sequences, which is the above-mentioned reward for the child.

The vibratory stimulation can even lead to pacification of users with symptoms of restlessness or hyperactivity. The tool can thus be applicable for basal stimulation as a vibrational relaxing stone. It can become a great tool for those who are looking for tactile and proprioceptive stimuli, bearing in mind that the earliest forms of interaction between a mother and child right at the prenatal stage are somatic, vestibular and vibratory.

The individual segments of the tool are made of wood. The shape and the material are selected so that they are comfortable for the baby to touch. Wood is a warm material, which bears vibrations very well and soothes the user at the same time. The shape of the whole product as well as of its parts have been molded for the hand of a child.

How advanced is the project?

Several prototypes have been manufactured. The shape has been studied to be soothing and fit a child's hand. The electronics inside are quite basic at the time, interacting with a vibration motor and an IR LED and receiver to detect touch.

Even if the functionality is limited for now, the device has been used in several care institutes for deaf-blind people. Feedback is incredibly positive and they want to try every new improvement and prototype.

Our goal is to improve the pebbles in order to provide a professionally-finished product. Planned improvements include:

  • Rechargeable battery. Disposable button cells are used now. We would like to seal the shells for good once assembled.
  • Inductive charging. A charging port requires a hole and a potential danger for blind people. Inductive charging pads could be integrated in the docking station.
  • Better touch detection - IR LED and receiver implies a hole in the shell, which is undesired.
  • A more reliable way for halves to detect if they are matched with their correct half.
  • Wireless communication to interact with the user: Change difficulty of the game, change vibrations according to the child's behavior, etc


Hardware files will be licensed under CC-BY-SA 4.0 and software files under MIT license. More files will be uploaded to repositories when the project evolves.

Awards with Loono

  • Finalist and winner in the Czech, National Award for Student Design 2015
  • Excellent Student Design 2015, The author gets Symbol Competition for Excellent Student Design 2015
  • Prize Exit Design awarded by Dean of the School of Art and Design, University of Jan Evangelista Purkyne
Exhibition with Loono
  • Project Loono...
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  • Loono, the rebirth, part 2

    Sebastien06/19/2017 at 07:16 0 comments

    For this second part, we will focus on the embedded electronics. As a start, let’s recap the functions that will be implemented.

    • Each half-bean should be able to interact with the user. That means detecting if the user is holding the shell, detecting if one half is mated with another half (and if it is the good one or a bad one) and answering in consequence through various vibration (variation of frequency, strength, duration, or altogether – think of a soothing, relaxing vibration for a match and a more angry one for a mismatch).
    • Each half-bean is energetically independent and should be equipped with a battery. In the first part, it was mentioned that the shells should be perfectly sealed, and no hole, contact or protrusion should be visible. Therefore, “wireless” charging should be implemented.
    • Finally, it could be interesting to implement some kind of logging in order to monitor the activity of the user (how successful the game was, how quick the child solved the game, after how many trials, etc.). This would allow monitoring by the parents or educators, whilst also allowing fine adjustment of the various parameters (difficulty of the game, strength or frequency of the vibrations, etc.) to adapt to the disability and sensitivity of each and every one. Since the shells will be sealed once and for all during manufacturing, this communication between the half-beans and the user as to be done wirelessly (Bluetooth, Wi-Fi or other). As a side note, this could also allow remote firmware upgrading if needed.


    The very basic functionality of vibrating is pretty easy to realize in itself. Vibration motors are available is many shapes and sizes, thanks to the cellphone industry. A special attention has to be paid in driving the motors in order to reduce consumption as much as possible, since the battery in each shell will most likely be pretty small. We definitely do not want to be charging the shells twice mid-game.

    State detection

    Detecting the user’s grasp is already more complicated. In the first prototype, this was done using and IR LED and receiver side by side. Although this worked, this solution requires a hole in the shell, which is undesired. Also, it detects when you put the shell upside down on a table, which is also undesired.

    So, we need to detect touch through a 2 or 3 mm wood shell, but also be able to distinguish between the user’s grasp and the shell simply resting on a table or sitting in its charging pad.

    One example of such problem if cooking plates controls. They use capacitive sensors placed beneath the glass surface, allowing detection of user’s touch above the glass surface. There is also some kind of algorithm that detects if a finger is touching one button, or if a pan or a wet rag is touching several buttons.

    If the inner side of the shell was equipped with an array of capacitive sensors, there could be a way to detect (with a slightly more complex algorithm than the one of cooking plates) the state of the shell. If the user is holding the shell with a full hand grasp, several sensors on both sides of the shell would be activated, or only small, isolated activations if the user is holding the shell with a pinching grasp. If the shell is resting on the table, only a small area would be activated. Last, if the shell is in the charging pad, only one half of its surface would be activated. Or something like that. This obviously needs some more thinking, and a lot more calibration afterwards.


    As the shells are independent and sealed, they need their own inner power supply. This achieved with a small rechargeable battery. In the first prototype, two non-rechargeable CR2032 batteries were doing the job, but this obviously won’t cut it once the product is sealed. The size available in a half-shell severely limits the size of the battery. According to early quick researches and what currently exists on the market, the battery could not be bigger than 500-600mAh @ 3.7V. Also, “Safety...

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  • Loono, the rebirth, part 1

    Sebastien06/07/2017 at 14:09 0 comments

    It has been a while since the first entry (life happens), but it only meant gaining momentum in order to jump further!

    The initial description stated that some prototypes have already been built. But since this is a work in progress, several improvements need to be done before the product reaches its completion.

    Therefore, let's start by listing what has been done, what is good in that and what needs to be improved or even rebuilt from scratch.

    For this first log, we will focus on the mechanical parts (the enclosure).


    A distinctive sign of Loono is its classy shell. A wooden, smooth, natural shell that consists in two parts satisfyingly mating. Hours of research and drawing have gone through this design, and it sure delivers. The shape is enjoyable to hold and play with, even for non-blind people. Thus, this should remain as is.

    However, there are several details that are less satisfying and require improvement.

    First, Loono will be handled by people with disabilities, who might not be fully aware of their environment. The shell needs to be completely shockproof so it doesn't crack when falling on the ground or even accidentally smashed on a table.

    Second, the shell should be completely sealed. Smooth, no holes, no protrusion, no electrical contacts. Remember, users will very likely not see the object and will discover it by touching with their hands or their skin. We do not want to risk any injuries that would ruin the experience.

    Third, the shell hosts the electronics inside. We will go in details about what it hosts later, but the inner surfaces of the shell will need a specific redesign to adapt to the upcoming changes.

    Finally, design for manufacturing. Prototyping CNCed wooden shells was rather expensive. Since Loono consists in several pairs of shells (at least 4, maybe more), each one should only cost a few $/€ to manufacture. When redesigning the shells, special care need to be taken to facilitate manufacturing (few operations, minimum loss of material, etc).


    For blind people, it is essential that things are always well in place, so they can find it with ease. Loono is no exception to that , and therefore requires a pad to put the stones aside when not using them. A pad already exists, but there is one problem.

    Spoiler alert on Part 2: Each stone will be equipped with a battery, with no external port to the outside world. Does that sound like inductive charging? Yes it does. In order to implement inductive charging, the emitter and receiver coils need to be placed specifically. The pad, as it exists now, might not be suitable for that, and will likely need a redesign.

    This is all for the mechanical part. Part 2 will deal with electronics and will not be as short as Part 1, so stay tuned and expect more! Comments, opinions and tips are more than welcome!

View all 2 project logs

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