Hello, I am Minna Pakanen from Aarhus University and I am presenting a pictorial about crafting a leather self-tracking device for pollen allergies. I have written this with Kasper Heiselberg, Troy Nachtigall, Marie Broe and Peter Krogh.
The need for the design came from respiratory medicine researchers who have been trying to collect data on patients’ allergy symptoms and medicine intake through web questionnaire that has been prompted with a text message every day at 7pm. However, the response rates have been low, and the researchers tasked us with finding a new approach for assisting patients in self-tracking their allergy symptoms and medicine intake in a motivating and in effortless manner multiple times per day and also while on the go.
When designing the device, we needed to consider both patient and healthcare professional’s needs. Meaning that the data collected by patient with the self-tracker, should be visualized; first, in interpretative visual manner on a mobile application for the patient and second, in analytical, abstract presentation for the doctor and allergy researchers. The aim of this system is to help patients to understand their illness and learn to manage it by finding the right medication pattern and places where they do not get symptoms. Analytical data is aimed to help allergy researchers and doctors form more informed diagnoses and develop better pollen medicine.
The motivation for using leather as a material for allergy self-tracking device came from observation that the current domestic healthcare devices rely on the ‘greyish-white plastics and steel’ look of hospital equipment or the contemporary ‘dark plastic and alumininum’ of smartphones and watches. This limit the user group of the devices, and medical aesthetics can even stigmatize the user. In contrast, we believe that leather as a warm, soft, inviting, and natural material enables the domestic healthcare device to be integrated into the patients’ every day as it fits better with other items user is wearing and carrying with.
The motivation for using leather as a material for allergy self-tracking device came from observation that the current domestic healthcare devices rely on the ‘greyish-white plastics and steel’ look of hospital equipment or the contemporary ‘dark plastic and alumininum’ of smartphones and watches. This limit the user group of the devices, and medical aesthetics can even stigmatize the user. In contrast, we believe that leather as a warm, soft, inviting, and natural material enables the domestic healthcare device to be integrated into the patients’ every day as it fits better with other items user is wearing and carrying with. The leather is created using tannins occurring naturally; such as tree bark, and cranberries.
Natural leathers continue to “sun tan” as they change colour under UV light exposure. They also absorb oils and display scratches with use far easier than other leathers. All beforementioned make the object made of vachetta leather to look and feel unique and we believe that it helps the user form an emotional attachment to it as every scratch and mark stand for a particular experience.
We initiated the shape explorations by looking for inspiration from pollen grains with various shapes, including triangle, globe, donut, ovals, and coffee bean.
The iterative ideation of the device was conducted through sketching, making physical mock-ups, and wet forming leather. The process ended up with five concept. Which features were combined into final, for example, three buttons (medicine intake, symptom and ‘all okay’) with click interaction, multi-wearability, and integration of a pillbox into the device. The pillbox was abandoned later due to the lack of space. In addition, we included automatic registering of the time and GPS location of the recording to be transformed into the application that also contains pollen forecasts. The wet forming of different shapes was conducted to explore how those would feel in hand. The oval shapes were perceived to be the most pleasing and was decided as the form to proceed with.
We explored different approaches for making buttons.
We explored different approaches for making buttons. We started with designing context inspired pictograms and laser engraving them on the leather. The symptom button (a) was inspired by pollen, medication button (b) from a pill, and ‘all okay’ (c) from a circle. Even though we liked the look of these engraved buttons, it was difficult to recognize them from each other in blind use cases.
We therefore carried on in exploring with wet forming of the shapes in this approach we cut the pictograms from thinner leather and glued them under the main leather piece and then after wet forming into final shape with mold (2a & b) it resulted pictograms that show as convex on the front side (2d). However, in this case it was even more challenging to distinguish three buttons from each other (2d). Therefore, we simplified button shapes into triangle, rounded edge square, and half-circle (2e-f). We also tried to make buttons to become more visible in the front side by forcing the leather down around the pictograms with a plastic stick during the wet forming (2f). However, the outcome was not visually satisfying.
Next, We decided to use an additional upper mold with holes shaped like the final buttons (3a) on top of the basic mold to make buttons appear more apparent on the front side (3b). Which lead to a visually more satisfying outcome. However, extra leather pieces on the backside did not work well with electronic switches. We, therefore, abandoned gluing additional leather on the backside.
To make buttons appear better on the front side without extra pieces on the backside, we modified the inner mold by gluing button shapes on it (4b). They were smaller than those in the upper outer mold layer (4a) to make room for the leather. These experiments ended up with distinctive buttons (4c & d) that worked well with electronic switches.
However, we needed to enlarge the device as electronics took more space and we laser cut the final molds from acrylics (4e & f).
Next there will be a video of the wet forming of the leather cover.
The leather is cut in the right size with the mold. 3,5 cm extra is added on the both ends of the upper mold for attachment straps.
The leather piece was sunk in approximately 60 Celsius water for a couple of minutes to wet thoroughly.
When no bubbles appear then it is soaked thoroughly.
The soaked leather piece is put in between the mold pieces and pushed in as tightly as possible.
The mold is then flipped around and attached to the table with clamps and left to dry until next day.
The mold is opened when leather feels dry enough.
The holes for stitching is punched with a leather hole punch tool and a cellidor head hammer.
The excess leather was cut away approxi¬mately 3,5 mm from the convex edge.
10mm wide strap was left on both ends of the top cover.
Attachment straps are thinned from the ends with a leather skiver tool so that sewing seam will not get too thick.
Finally, a hole for the charger was made with a revolving punch plier and knife.
In the mean while the electronics was built by applying a stacking principle. Lowest in the stack is the Li-po battery that provides enough power for two to four weeks of use in a row. Above the battery is a TTGO T7 esp32 development board and a small coin vibrator for giving haptic feedback for pushing the buttons.
The support structures are made of acrylics glued together with double-sided soft tape.
The finished stack and its charging port are glued in their place in the back cover a with hot melt adhesive.
Next tehre will have a video of the sewing and finishing the device.
Leather sewing yarn is taken 6,5 times the length of the stitching hole rim.
Both ends of the yarn are threaded to sewing needles.
The yarn is locked in each needle by pushing the needle three times through the yarn and pulling yarn loops over the needle.
Next the electronics stack is clued inside of the leather covers with double sided soft tape
Sewing is initiated by pulling the needle through both leather pieces, until an equal length of yarn is on both sides.
The needle on the right or backside is pushed through the next hole until a small loop of yarn is left on the right side.
The needle waiting on the left side is pushed through the same hole until similar loop of thread is left on the left side.
The stich is tightened while holding the device in between hands and pulling simultaneously the both yarns.
This procedure is repeated until the rim of stiches is ready. To end the stitches, the needles are pulled again through the second to last stitch, and then to the backside and yarn is cut short.
The edge is made smooth by removing the exes leather with a sharp knife.
The finishing of the edge is done with applying burnishing gum on it and polishing it with an edge polisher.
Finally, an attachment ring was put into the attachment strap loop to make it possible to attach the device on clothes, keys, or bags.
Thank you for you attention and iwe are happy to answer your questions if you have any.