Grip strength predicts death better than blood pressure. A new wearable sensor made of folded paper could finally let you measure it at home.

The PURE study, published in the Lancet in 2015, followed 139,691 adults across seventeen countries and found that every five kilogram drop in grip strength was associated with about a sixteen percent higher risk of dying of any cause. Compared directly against systolic blood pressure, grip strength was the stronger predictor, for all-cause mortality and cardiovascular mortality both. It is one of the most striking longevity biomarkers in medicine, and one of the least measured.

This episode covers a 2025 Biosensors paper from National Taiwan University and National Yang Ming Chiao Tung University that tries to fix that. The researchers screen printed airlaid paper with graphene ink, baked it, and folded it using origami into a knot that forms its own wearable ring. Worn on the middle finger, the paper sensor reads grip strength. Moved to the thumb, it reads pulse and pulse transit time, a cardiovascular biomarker that normally requires clinical equipment.

The sensor contains no chip. It works on electrical contact resistance, where folded conductive layers touch at more points under pressure, so the geometry of the origami fold is the measurement itself.

Brett Beckermann also covers what the paper gets wrong: no sample size anywhere in the study, a signal that saturates under hard grip, environmental performance claims with no supporting data, and a device wired to a laboratory bench in a paper that proposes people use it at home.

Topics: grip strength and longevity, wearable health sensors, origami engineering, graphene, pulse transit time, biomarkers, aging and muscle mass, flexible electronics.

Source: Karmakar, R.S., Lin, H.-F., Huang, J.-F., Chao, J.-I., Liao, Y.-C., & Lu, Y.-W. (2025). A multi-layered origami tactile sensory ring for wearable biomechanical monitoring. Biosensors, 15(1), 8.

Spent coffee grounds are almost pure carbon once dried, which is exactly what sits inside the lithium-ion anode in your phone. Researchers at Chungnam National University and KAIST skipped the furnace entirely and carbonised coffee waste with a femtosecond laser instead.

One dial on the machine decided whether they got hard carbon or graphene. And the sample everyone would have bet against ended up holding 54% more capacity than the commercial hard carbon batteries use today.

Ten minutes, no jargon, no PhD required.

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