# Foam-Based Wearable Devices Embedded with Shear-Thickening Fluids for Biomedical Protective Applications

## TL;DR

This paper introduces wearable foam devices with shear-thickening fluids that stiffen during falls to protect against hip fractures in the elderly.

## Contribution

A novel wearable device using shear-thickening fluids in foam structures to reduce impact forces during falls is proposed and tested.

## Key findings

- STF-filled foam devices reduced induced strain by 30% during impact tests.
- 3D-printed TPU devices with localized STF reduced strain by 50%.
- The device remains soft during normal use but stiffens on sudden impact.

## Abstract

Falls are a leading cause of bone fractures among the elderly, particularly hip fractures resulting from side falls. This research deals with the feasibility of application of shear-thickening fluids (STFs) to design self-protective wearable devices to rapidly respond to sudden impact due to falls. The device consists of a lightweight, flexible foam structure embedded with STF-filled compartments, which remain soft during normal movements but stiffen upon sudden impact, effectively dissipating energy and reducing force trans-mission to the bones. First, a foam-based sandwich panel filled with STF is fabricated and subjected to several falling scenarios through a ball drop test. The induced strain of the device with and without STF is measured using Fiber Bragg Grating (FBG) sensors. Then, the effect of localized STF is explored by fabricating a soft 3D-printed (TPU) sandwich panel filled with STF at selected cavities. It was observed that the application of STF reduces the induced strain by approximately 50% for the TPU skin device and 30% for the foam-based device. This adaptive response mechanism offers a balance between comfort and protection, ensuring wearability for daily use while significantly lowering fracture risks. The proposed solution aims to enhance fall-related injury prevention for the elderly, improving their quality of life and reducing healthcare burdens associated with fall-related fractures.