It
is implied that this is for adults:
> Moreover, to measure urine sugar levels in elderly or long-term care patients, sensors can be embedded directly into their diapers.
The paper itself explicitly states that it is for long-term care -- from its abstract:
> A self-driven sensor that can detect urine and urine sugar and can be mounted on diapers is desirable to reduce the burden of long-term care.
Modern diapers are remarkably complex. The super-absorbent polymer inside is really quite ingenious; and it's my understanding that brands have proprietary chemistry going on inside to prevent urea breaking down into ammonia and producing a smell, and damaging the patient's skin.
I sustained an injury to my spinal cord earlier this year, and all of this became much more personal – I have to say, compared to a urinary catheter (a device that can only be described as 'evil and tortuous') diapers are positively idyllic...