iFixit’s Kyle Wiens has “hot-wired” Apple’s new iPhone 16 in the name of repairability — investigating a clever new adhesive for the battery that can be made unsticky by the application of a short, sharp electric shock.
“The adhesive that secures the battery, in the [Apple iPhone 16] vanilla and Plus models, is this fancy new sticky stuff that can debond when you pass an electrical current through it,” Wiens explains. “That means no more reliance on finicky, brittle adhesive strips, just a consistent, easily repeatable process. It will require a new tool, of course.”
The clever electrically-releasable glue appears to be based on an approach detailed in a 2021 paper by Clara Anduix-Canto and colleagues in which adhesive layers are placed on top of and underneath an aluminum substrate. By applying electricity, the aluminum substrate is oxidised and aluminum ions migrate from the substrate into the adhesive to debond it — allowing stuck parts to be removed without the usual heat-and-force approach.
There is, however, a catch. In order to actually have the adhesive work, the substrate has to be sticky on both sides. Which side gets the aluminum ions when you apply a current depends entirely on the polarity: get it right, and removal of a failing battery will leave behind a squeaky-clean phone ready for its replacement; get it wrong, and you’ll leave the adhesive behind in the phone and remove a squeaky-clean faulty battery instead.
“Our cable was set up to deliver 12V, and since Tesa suggested that their adhesive would release in 60 seconds at 12V, we waited a minute: Sure enough, the battery lifted out with no force, and the case underneath was almost residue-free (though the battery side remained tacky),” Wiens recounts. “You’ll probably still want to take a pass with isopropyl alcohol before you put a new battery in, but you won’t have to scrape out adhesive strip remnants like in iPhones of yore.”
Get the polarity right and you’ll have a clean phone (right) with a sticky battery; get it wrong, and the opposite (left). (📷: iFixit)
While that’s a promising start, it remains to be seen how the adhesive reacts over time: Apple’s official repair documentation for the handsets suggests that as the adhesive ages it may take longer to release, or require more voltage. To experiment with the variables, Wiens tried both higher and lower voltages — seeing the adhesive release in just five seconds at 20V, but taking six minutes at 5V.”
Wiens’ full write-up is available on iFixit, along with notes regarding the new design’s improved thermal handling for on-device machine learning and artificial intelligence (ML and AI) workloads and a provisional repairability score of 7 out of 10 — “a significant upgrade from last year’s model,” Wiens notes.
