Illuminating an LED by a piezoelectric polymer sandwiched with a conductive elastomer

Description

Alternative energy sources become increasingly crucial for all sectors. Piezoelectric Energy Harvesters (PEHs) are materials which can self-generate electricity while being subjected to dynamic mechanical conditions. A potential application of this material is its use in vehicle tires, since the tires are driven under dynamic mechanical conditions. This includes the hypothesis that, if a PEH is attached to a running tire, it would also be able to generate electricity. The present work attempts to prove this concept by developing a PEH prototype for tire application.
Under tire-rolling conditions, a PEH needs to be flexible. Therefore, two key elements were selected: 1) a piezoelectric material – PolyVinyliDene diFluoride (PVDF) film; and 2) an electrode – a conductive elastomer filled with carbon black and Single-Wall Carbon NanoTube (SWCNT). The prototype was designed into a flexible cylindrical shape in a sandwich-like configuration [1]. It was fabricated by inserting a PVDF film in between two conductive elastomer sheets. There were crucial aspects required to be investigated and to be optimized during this development: 1) the electro-conductivity level of the elastomer; 2) the adhesion between the PVDF and the conductive elastomer; and 3) the performance assessment of the evolved PEH. It was shown that the optimum amount of SWCNT was at 6 wt% of its 10 wt% masterbatch in a process oil. The adhesion between the interfaces was improved through a surface modification of the PVDF film by introducing oxygen functional groups via a plasma treatment and further reacting with a thiocyanate silane [2]. The successful surface modification of the PVDF film was affirmed by X-ray photoelectron spectroscopy. T-peel and fatigue tests showed durable and stable adhesion between PVDF and conductive elastomer, confirming that the silane used can effectively bridge the two components.
To validate its piezoelectric performance, the PEH prototype was subjected to a dynamic mechanical application simulating a tire-rolling condition. It was estimated to produce 28 µW cm2 which can lighten an LED light.

Period	1 Jul 2024 → 4 Jul 2024
Event title	German Rubber Conference, DKT 2024
Event type	Conference
Location	Nuremberg, GermanyShow on map
Degree of Recognition	International