Today's KNOWLEDGE Share : Dielectric Constant vs. Shielding

Today's KNOWLEDGE Share 

Dielectric Constant vs. Shielding: The hidden physics behind EMI protection!

In the race to develop the next generation of EMI shielding materials, we often focus on conductivity as the key factor. But what happens when a material has poor conductivity yet a high dielectric constant (εr)? 

📡 The Impact on Shielding:

⚡ Low Conductivity → Weak Reflection

Metals shield via reflection, but if a material lacks conductivity, it won’t create a strong impedance mismatch. Instead of bouncing waves back, it lets them pass through!

🔥 High Dielectric Constant → Potential Absorption

A high εr means the material stores more electric field energy. If it also has high dielectric loss (tan δ), this stored energy is converted into heat—enhancing absorption-based shielding (like radar-absorbing materials).

🛠 Optimizing for EMI Shielding:

✅ Add non-metal conductive fillers (Graphene Nanoplatelets, CBs, CNTs) to improve reflection & absorption.

✅ Use foamed or layered structures to create multiple internal reflections.

✅ Introduce magnetic fillers (Fe₃O₄, Ni, ferrites) to leverage magnetic losses.

At Graphenest - Advanced Nanotechnology, we fine-tune the balance between conductivity, dielectric properties, and structure to create high-performance shielding solutions for e-mobility, advanced electronics, and energy storage.

source:Bruno Reis Figueiredo

#EMIShielding #Graphene