Invisible Shield against Electromagnetic Interference

• 19 Aug 2020

Why in News

Recently, scientists from the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have designed a metal mesh structure to construct an invisible shield against Electromagnetic Interference (EMI).

• CeNS is an autonomous institute under the Department of Science & Technology, Government of India.

Electromagnetic Interference

• EMI is an electromagnetic emission that causes a disturbance in another piece of electrical equipment.
  
  • Any device that has an electronic circuit can be susceptible to EMI.
• It compromises the performance of electrical equipment by obstructing and degrading data, sometimes even losing data completely.
• EMI can be attributed to a wide span of the electromagnetic spectrum including radio and microwave frequencies.
• In 1933, the International Special Committee on Radio Interference (CISPR) was created to address emerging concerns over EMI.

Key Points

• Metal Mesh Structure:
  
  • The scientists have developed a copper metal mesh on polyethylene terephthalate (PET) sheet, instead of continuous film, which exhibits a visible transmittance of about 85%.
    
    • Transmittance describes how much light passes through a sample. In other words, it is light that is not absorbed, scattered, or reflected. It is usually measured in percentage.
  • The metal mesh networks on the substrate are more transparent than continuous film because it covers only 7% area of the substrate, unlike 100% coverage of continuous film.
  • Metal mesh provides better electromagnetic shielding compared to the same thickness of continuous metal film where transparency can be compromised.
• Benefits:
  
  • The main purpose of the EMI shield is to isolate a device's energy so it doesn't affect anything else and blocks external energy from getting in.
    
    • Without shielding, electronics wouldn't function as designed or may even stop working altogether.
  • This ‘invisible’ shield can be used in various military stealth applications and can cover electromagnetic wave emitter or absorber devices without compromising aesthetics.
    
    • Besides the physical shape, reducing the electromagnetic signature, which includes radar waves and radio signals, is an important element for enhancing the stealth capability of a weapon platform.

Source: PIB