the Sociable Pint

The very first prototype of the circuit.

The original 3D CAD design of the original module casing.

In order to test the capabilities of the sensors and wireless network, I experimented with few basic versions of the final circuit.

After I was satisfied with the preliminary testing and circuit design, I sent out the circuit board to be printed.

This is what the circuit looked like after I soldered on all of the components. Because I have to cram so many components underneath a little pint glass, I settled on a 3 tier design.

The completed circuit securely fitted together.

The first three glasses.

This is the first prototype of the housing for the electronics. It has been developed in the 3D modeling program, SolidWorks, and sent to a rapid prototyping machine to be formed.

I originally considered using the prototype as a mold to produce plastic casings. I have no experience in mold making so I consulted people with experience in this matter. I was informed that the tolerances of a 1/16 inch that I am dealing with could be problematic in the mold making process.

Considering this information, I tested the robustness of the ceramic prototype and was pleasantly surprised. I subjected the prototype to abuse (i.e. by dropping the prototype on floor, by squeezing it in a clamp) and it is apparent that it is more tolerant to strains than the pint glass that it will be affixed to.

The rapid prototyping process is relatively inexpensive (>$5 per piece), and in small quantities (>20 pieces), it seems economical to just use the ceramic prototypes instead of producing plastic versions of the casing.

I wanted to squeeze the electronics into a smaller area, but with the tools that I have access to, the casing that I have produced seems like the smallest I can go at this point. My desire was to fit everything in a 1/2 inch puck glued to the bottom of the glass, but the size of the 850 mA Li-ion battery alone makes this desire improbable. I may be able to go smaller in future iterations of this project, but for now, the size of the casing which I am using is acceptable.



Affixed to the pint glass, the image above is what the complete module will look like. Unfortunately, I have not completed the electronics that will be put inside.

I have attached a clear conductive plastic film that skirts the glass to the capacitance sensor in the glass. I have also experimented with other methods such as conductive paint. Conductive paint is opaque and it doesn’t adhere to the glass surface well. I tried creating a meshed mask and then painting on the conductive paint in attempt to give the touch surface of the glass a somewhat transparent appearance, but even covering this coat with a clear liqueur, the paint still has problems sticking to the glass.

The plastic film has achieved the best results even though it has its own problems. For one, it gets dirty really easily. Fingerprints seem to affix themselves to the plastic film quite easily. Also, liquids easily get caught in between the glass and the plastic film. I ameliorated this problem by applying a clear paint around the edges of the plastic. At this point, the conductive plastic is the best solution, but I really want to find a better solution in the future.

Working out the shape of the shell that needed to be affixed to the pint glass, I started to sketch out a design on paper that I would later draft in SolidWorks.

Through this process I had to work out a number of problems. The most important problem was how I was going to fit all of the electronic components underneath the glass. I needed to create a design that maximized space of the components. I also had to pay attention to how the design would allow for the placement of a RGB LED and that would allow for easy accessibility if I needed to open it up and change things around. The package design also needed to be robust in case it is dropped and stable so the glass wouldn’t be at risk of falling over.