Our team was tasked with creating a sensory board for a child struggling with fine motor skills. The main goal of this project would be to create a board that would allow the child to build fine motor skills through the various mechanisms and activities that would be present on the board. Additionally, a choice board would be included that would allow the child to build the ability to make decisions.
The fine motor board is meant to train fine motor skills by giving feedback within the toys. Some toys may light up or activate a speaker in response to pushing a button or a door may open after a lock or some sort of mechanism is interacted with.
While researching the options for a choice board, we looked into child-safe materials as the child is only 2 years old. We found that most children’s toys use special kinds of plastic such as PLA or polyethylene. We also looked into similar products already available on the market. We found walkers with a choice board built into them, activity boards, and toys with a variety of different toys and mechanisms built into them when trying to decide how to design ours.
The first concept we came up with was to have a board that would attach to the front of the walker which seemed to be the case with many different children’s toys on the market. However, the main issue with this design is that it can’t be used while in the walker, so it would only be available when the toddler is sitting, meaning that attaching it to the walker wouldn’t be necessary.
The second idea we had was building a busy board similar to the ones on the market and finding a way for it to latch onto the walker on the top. This would allow for it to be used while standing in the walker. Similar to a high chair, the busy board would be in a similar position as a tray would be, allowing for it to be interacted with standing in the walker while also being detachable.
The final concept we discussed was for a ‘board’ that wouldn’t attach to the walker and would instead take the form of a cube. The family seemed to be interested in a product that wouldn’t be attached to the walker at all, so we decided that this design would be the best way to accomplish it. While it doesn’t attach to the walker, the number of sides means that more activities can be placed on each one and different sides can have different skills allocated to them.
The design concept we finally decided on was the cubic design. We decided that making the object separate from the walker, but still accessible was the best course of action. This allows for greater portability as well as more toys to play with and will not impede any movement on the walker or require being out of the walker to interact with.
Our selected design is going to be a cube with four different sides of activities and a handle on top. Each different face is going to contain different activities. One face will have the choice board with several buttons. The others will have mirrors, doors, locks, switches, a calculator, and other objects.
The design has five available faces(including the top) so we allocated various objects to each of them. One of the faces will have the choice board on it, meaning that buttons will be present for the child to press. The top side will have a toy phone on top that can be played with. Another face will have small doors that open and close as well as knobs and mirrors as well as a bell. Another face will have a peg that is led along a wooden track. The final side will have switches and a calculator on it. There are also plans for some form of rotational mechanism on the bottom that will allow for each side to be easily accessible. The box itself is going to be made out of a 3d-printed frame with wooden panels for the faces and an acrylic covering for visual and strengthening purposes.
The group places a high priority on ensuring the structural integrity of the frame. In this engineering analysis, we aim to determine whether the frame can withstand the typical forces exerted by a 2-year-old girl. To simplify the analysis, we assume a mass of 12kg for the average 2-year-old girl, which translates to a force of 117.72N.
This force of 117.72 Newtons is expected to represent the maximum force a 2-year-old girl can exert on the frame, as most adults, especially children, cannot exert forces greater than their own body weight. The frame is constructed from PLA material, and we conducted a stress analysis simulation with the 117.72N force distributed across the top of the frame.
The results of the displacement simulation indicate that the frame experiences a maximum bending of 0.0214mm at the joints of the quarter sections. Fortunately, this displacement is not significant enough to affect the functionality of the toy panels or the toys themselves. However, it’s important to note that this displacement simulation assumes the material won’t break under the applied forces.
To ensure the frame doesn’t break, we must also consider the safety factor, which is a ratio of the maximum stress the frame can withstand before breaking to the supplied stress. Therefore, a higher safety factor implies greater safety. The safety factor simulation clearly demonstrates that the frame is far from reaching its breaking point, which is at 0.
The fabrication process for us involved 3d printing the various parts in order to assemble the frame. Because there were no printers available big enough to print the entire frame, we opted to split it into parts which would be connected through heat-set inserts and small pegs for stability between sections. From there, we used the laser cutter available in the lab to cut out the drawings for each of the faces onto acrylic. We ran test runs on wood first to make sure the shapes aligned before making the same cuts into our limited acrylic. From there, the pieces of wood were glued together with the top layer being the glossy acrylic. The various toys and gadgets are attached with velcro for easy removal for changing batteries or adjusting the sound on the recording buttons.
While the project does not involve too many mechanical components, all of the battery operated devices function properly and the door components seem to operate as expected as well.
The magnets to hold photos in place can be rather small so when they’re not in use it’s best to safely store them within the container and keep them out of reach of small children. While the box is sturdy, do not attempt to apply excessive force like sitting on the device. The lights on the switches can be a bit bright so don’t stare at them for extended periods of time when lit. Do not attempt to pull apart the faces of the box. To record new audio on the buttons, press the record button and speak into it and then release once the sound is finished.
Our project was able to provide several different objects that light up or play sounds in response to performing some sort of hand exercise. In this regard, the fine motor skills should be able to be effectively trained by using this device. There are a few mechanical components such as a doorknob part for practicing other movements. In the future, it seems as if it would be best to order parts earlier as several crucial components arrived later than expected, causing delays in the assembly of the project. One potential way to remedy this would be to set deadlines for when to finish certain stages of the project so the design process is more seamless and plenty of time is left to wait for parts and to find times for everyone’s schedule to build the project.