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Porous Conductive Hybrid Composite with Superior Pressure Sensitivity and Dynamic Range

Accepted version
Peer-reviewed

Type

Article

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Authors

Stevens, M 
Hasan, T 

Abstract

Porous conductive composites hold immense promise in flexible sensors and soft robotics due to their pressure- responsive electrical conductivity. Unlike non-porous composites whose pressure sensitivity is limited by relatively high elastic modulus, porous materials show improved pressure sensitivity owing to their lower stiffness. Despite this, existing porous composites still suffer from insufficient pressure sensitivity or narrow detection ranges, severely restricting their applications. This work presents a liquid metal hybrid filler porous composite to address these issues. Through experiment and simulation optimization, the composite exhibits a conductivity increase of 5 order- of-magnitude over 0 – 250 kPa, demonstrating a 900% higher pressure sensitivity than the best non-porous counterpart in this work. The composite maintains a highly linear response (R² of 0.999) over an exceptionally wide dynamic range up to 8.9 MPa, with a pressure sensitivity of 8.1 MPa‾¹, surpassing the state-of-the-art in both pressure range and sensitivity. A proof-of-concept pressure sensor array further demonstrates the composite’s excellent sensing performance, showing stable response under 100-cycle loading with a measured pressure deviation of only 1.4%, outperforming existing commercial pressure sensors in terms of sensitivity, detection range and cyclic stability. Our porous material design strategy opens doors for high sensitivity pressure sensors in wearable devices, flexible electronics and soft robotics.

Description

Keywords

3403 Macromolecular and Materials Chemistry, 34 Chemical Sciences, 40 Engineering, 4009 Electronics, Sensors and Digital Hardware, 4016 Materials Engineering, 7 Affordable and Clean Energy

Journal Title

Advanced Functional Materials

Conference Name

Journal ISSN

1616-301X
1616-3028

Volume Title

Publisher

Wiley
Sponsorship
Royal Society (NIF\R1\211458)
Royal Society (NIF-R1-211458), IIB project funds from the Electrical Engineering Division, Cambridge University Engi- neering Department