Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras

A Conducting Electrochromic Composite of Metallic Nanowires And Multi-Coloured Thermochromic Materials

Categories for this Invention

Advance Material & Manufacturing | Chemistry & Chemical Analysis

Industry: Electronics Smart Devices, Manufacturing & Coatings, Textile Industry

Applications: Customizable Surfaces, Smart Windows & Glass, Consumer Electronics, Architectural Coatings, Display Technology

Market: The global Electrochromic Materials Market size is forecast to reach $1,910.3 million by 2025, after growing at a CAGR of 6.9% during 2020-2025.

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Problem Statement

  • Current electrochromic materials, particularly metal oxides and conducting polymers, involve complex deposition processes and limited flexibility, making it costly to manufacture and inflexible for various uses.
  • Existing devices lack diverse color variations, restricting their adaptability to meet the demands for a broad spectrum of colors in electrochromic applications.
  • Conventional electrochromic devices need a multi-layered structure & specific electrode layers, which inherently limit flexibility and ease of production, leading to complex design & fabrication.
  • Hence, there is a need for a cost-effective, easy to manufacture an electrochromic composite which is flexible & made of a conducting material.


  • The present patent invention discloses a conducting electrochromic composite comprising of metallic (silver) nanowires, thermochromic material, and optionally a conducting polymer. FIG 1 depicts the drop cast patterns of the thermochromic nanowire composite ink in different colours. Colour changes to white with voltage supply & returns to its original colour once voltage is removed.

Key Features / Value Proposition

  • The composite is a flexible conducting material, relatively easy to manufacture and of low-cost, easy to cast & drop.
  • The conducting electrochromic composite comprises 4-6 wt% of metallic nanowires, 2-6 wt% of thermochromic material selected from a material that reversibly changes its colour with temperature, and optionally 10-15 vol% of conducting polymer.
  • The final material is prepared in a dispersion form, for easy application over the substrate using any conventional solution-based deposition techniques.
  • A single layer deposition is sufficient, without needing any complex multi-step deposition processes currently in use to fabricate electrochromic devices.
  • Dispersion has very low post-deposition annealing requirements (100 °C for 1 h).
  • Support multiple colors and can be controlled by the applied voltage.

Questions about this Technology?

Contact For Licensing

Research Lab

Prof. Parasuraman Swaminathan

Dept. of Metallurgical and Materials Engg

Prof. Debdutta Ray

Dept. of Electrical Engineering

Intellectual Property

  • IITM IDF No: 2032
  • IP No: 401967 (Granted)
  • PCT: PCT/IN2021/050569

Technology Readiness Level

TRL – 4

Technology validation in Lab

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