Upcycling E Ink From Damaged E Readers to Create Irregularly Shaped Display Widgets:

In this Instructables page I’ll describe a process to take apart damaged E readers and extract the E ink from within with the purpose of creating custom shaped display widgets. The gif above shows some of the objects that we created - see this video for higher resolution pictures! This project was developed as a research project under the title FabricatINK at the University of Bristol and more information can be found in our video and our academic paper

• Damaged E readers (we suggest one E reader per ~4cm square of display widget you want to build)
• Screw drivers/torx
• Allen keys
• Glass beakers
• Paint Brush
• Stanley knife or waterjet glass cutter
• IPA
• Acetone

We started by gathering damaged kindles from Ebay. We found the best results, most commonly occurring and easiest access to the E ink from kindle 4s. For the whole project we bought about 35 damaged models with an average cost of around 6GBP.

We then continued to disassemble the devices until we were left with a “slide” of Eink – a layer of PET with transparent conductive material (ITO) layered on top of it and a layer of E ink microcapsules mixed with adhesives layered on top of that. 

The first step was to disassemble the casing of the E ink. We started by using a screw driver and allen keys to pry apart the casing. We didn’t worry too much about snapping the plastic as this was recycled/disposed of and no longer used (all by products that could be recycled were).

We used Torx screw drivers to remove the screws (there are about 20 of them) in the device which allowed detachment of the circuit board and other casing parts.

We carefully removed the lithium battery from the casing. This is stuck down using a strong glue. This is probably the most dangerous part of the process so please be very careful if carrying this out yourself. We used a paint brush to gently apply IPA to help dissolve the glue and release the battery.

Once the battery was removed we are left with our core component containing the E ink – a metal frame supporting a layered structure of glass, plastics, adhesives, electrodes and conductive materials. Our plan at this stage is to use a solvent to loosen the layers and remove the E ink from the glass/plastic/ etc and we can then use this active material to build our widgets.

We carried out a bunch of informal experimentation to work out how best to breakdown the glue holding the layers together without damaging the E ink layer itself or the transparent conductive material underneath it. We ended up finding a fine balance between strength of solvent that the layers were left to soak in (more solvent risks greater damage), size of the pieces of material we left to soak (smaller pieces have a greater perimeter to area ratio providing more entry points for the solvent but conversely give us less options when we actually want to use the material in cohesive sheets!) and time left to soak (with greater damage being risked over a larger amount of time.

We ended up using a waterjet cutter (although this can be done through careful scoring of the glass using a stanley knife) to split the screen into six parts. Splitting into six reduces the area of each piece and increases its perimeter allowing us to use a solvent (acetone) to dissolve the glue between the E ink and the glass. We observed this size (~4x4cm) to be most effective for producing slides with minimal damaged E ink and maximal area. The screen segments soak (c) for approximately 96 hours (±24 hours) to allow permeation of the acetone into adhesive layers. The pieces are then gently pulled apart (d), giving six slides with varying amounts of E ink on them.

For separating the layers, we tried IPA, Acetone and water at different temperatures over different amounts of time (up to 336 hours) to calibrate the balance between loosening the adhesive and damaging the microcapsules. Prolonged exposure to strong solvents (e.g. acetone) damaged the E ink particles themselves but such a strong solvent was necessary to loosen the glue used between the layers of the E reader. If the segments of an E reader display were left too long in the solvent, or were too small, the E ink microcapsules get damaged. If they were not left long enough, then the adhesive between layers was not sufficiently loosened and so when the layers were separated, the E ink was torn into smaller sections and rendered unusable. The variability of the method (largely due to E reader damage levels) meant that even once we had optimised the process, there was up to 50% waste of E ink.

Unfortunately I’m going to leave you hanging for a bit. In the next instructables I’ll post the fabrication process we came up with for creating the custom shaped display widgets. If you are impatient and want to know how then do check out our official project materials for an overview! ( Academic paper and video presentation)