Sustainable EMI Shields from Graphite-PVDF—A Scalable Solution for the 5G Era

Identifying the Issue

• The projected demand for EMI shielding materials for the purpose of protection of high-end sensitive electronic devices is rising due to the expansion of 5G telecommunication services, digitization, and the electronics industry.
• Many currently existing EMI shielding materials and techniques are energy-intensive to produce, or involve hazardous precursors or solvents, thus limiting environmental safety and scalability.

Objective of the Research

• To fabricate EMI shields having high shielding effectiveness by a sustainable and facile method using graphite and PVDF
• To investigate their shielding and electrical properties with variation in weight% of the constituents and with thickness of the shield to arrive at the optimum parameters for shielding.

Who should read this?

• Professionals working on EMI shielding materials and sustainable fabrication.
• Those interested in the electrical properties of PVDF-Graphite composite, and its compositional and thermal properties

Solution

A simple, scalable, and eco-friendly method of blending and pressing, followed by low temperature annealing with negligible solvent use to fabricate EMI shields using Graphite and PVDF.

Key Features and Benefits

• Graphite-PVDF composites developed using the scalable, and energy-efficient method showed tunability in their electrical and dielectric properties.
• The Graphite-PVDF composites exhibit electromagnetic interference (EMI) shielding effectiveness up to 50 dB in the X-band microwave region, making them promising materials for lightweight, cost-effective microwave shielding applications.
• The composite shields also exhibited suitable mechanical properties required for EMI shielding applications.
• As the technique required very minimal use of organic solvent, it is environment friendly while being scalable.

Impact

• Graphite-polyvinylidene fluoride (PVDF) composites preparation by a novel, energy-efficient and scalable route.
• Electrical conductivity tuned from 10⁻⁷ to 1 S/m by increasing graphite wt%.
• At 30 wt% graphite: maximum dielectric loss ~5000, absorbance = 42% & SE A = 86%.
• Dielectric constant and loss are large above the percolation threshold of 25 wt%.
• High SE_T of 30-50 dB achieved in X-band microwave region for 20–40 wt% graphite.

Team

1. Priyanka Verma (first author) (SSSIHL)
2. Deepa Seetharaman (Corresponding author) (SSSIHL)
3. Bharat Srimitra Mantripragada (JAIST)
4. Noriyoshi Matsumi (JAIST)

Title of paper: “Graphite‐PVDF Composite Sheets Fabricated via a Facile and Scalable Technique for Electrical and EMI Shielding Applications”

Read Paper Here: http://doi.org/10.1002/pc.30054

Fig 1: Fabrication of graphite-PVDF composite shields, variation of electrical properties and electromagnetic interference shielding performance with graphite wt%, shielding mechanism and frequency dependence of SE_T, SE_R, and SE_A (in dB)