Noise pollution is a growing concern in homes and workplaces, making acoustic solutions more important than ever. This project explores the potential of corn cobs (an agricultural by-product) to create sustainable acoustic panels. The goal is to offer an alternative to conventional soundproofing materials that is both eco-friendly and practical for real-world use.

Traditional acoustic panels are often made from synthetic materials like mineral wool, foam, or fiberglass. While effective, these materials come with environmental downsides, including high carbon footprints, waste generation, and, in some cases, the release of volatile organic compounds (VOCs) that can affect indoor air quality. This project takes a different approach by repurposing agricultural waste into a functional and circular product.

To test the concept, a prototype panel was developed. It measures 260 cm long, 30 cm wide, and 3 cm thick, designed to fit into U-profiles that attach to a floor-to-ceiling frame. The sound absorption coefficient was measured at approximately 0.35, meaning it provides some noise reduction but still has room for improvement. Mechanical tests revealed that the panel’s bending and tensile strength are lower than standard requirements, highlighting the need for a stronger or more suitable binder.

Despite these technical challenges, the project has promising advantages. Corn cobs are widely available and inexpensive, making them a cost-effective raw material. The panels support a strong sustainability narrative, helping brands improve their eco-friendly positioning. They also do not emit VOCs, making them safer for indoor use. Aesthetically, they have a neutral, modern appearance that can suit various interior styles, and their customizability allows for different design possibilities.

However, there are still some limitations. The natural inconsistencies of the material, along with its sensitivity to moisture, could affect long-term durability. Some users might also question its strength, especially compared to established alternatives. The texture of the panels may not appeal to everyone, and while the production process is scalable using hydraulic pressing, setting up large-scale manufacturing could be costlier than expected. Additionally, competing with well-known brands will require strong market positioning.

To make the product commercially viable, key aspects such as cost, regulations, and consumer demand need further evaluation. The main target audience includes first-time homebuyers and renovators who prioritize sustainability, but the panels could also be applied in commercial spaces. The next steps will focus on improving strength and moisture resistance while maintaining environmental benefits.

This project demonstrates how agricultural waste can be transformed into useful, sustainable materials. While further refinements are needed, corn cob acoustic panels have the potential to become a real alternative to conventional options. By balancing sustainability, function, and design, they could contribute to a more circular and environmentally responsible construction industry.

Electrochromic materials exhibit a reversible color change that is triggered by an applied voltage. Controlled color change, low voltage operation and the memory effect are three unique material properties defining electrochromic materials. As a result of an electron transfer or redox reaction, the material is able to switch between its bleached (transparent) and colored state. As this color change is a chemical reaction, it only requires an applied voltage to trigger and complete the electron transfer, thus afterwards the applied potential can be removed and the material will stay in its current state; i.e. the memory effect. Electrochromic materials are processed into a sandwich structure of thin layers that enable it to change color when a voltage is applied to it; i.e. an electrochromic device (ECD). An ECD operates through two electrodes that are connected to both the positive and negative of the voltage-source, and the two electrochromic layers. These electrochromic layers are separated by an electrolyte, that allows ion transfer, enabling change of color. Optimizing this layer structure, results into the definition of four stacking sequences, based on their vertical or co-planar stacking sequence (i.e. vertical stacking of the EC layers or merging of both EC layers in the same layer with separated electrodes) combined with the substrate used; conductive and insulating. These four stacking sequences are characterized on their transparency, shape/pattern changing abilities, coloring, design of the images displayed and interaction between the two EC layers; i.e. technical characterization. As result of this material characterization, ‘the puzzle of electrochromism’ is designed. ‘The puzzle of electrochromism is an edge-matching puzzle, with as goal to puzzle four geometric shapes by matching the sides of the adjacent puzzle pieces. Solving this puzzle communicates the goal of the demonstrator (i.e. the technical and experiential characterizations) to the puzzler, while emphasizing the simplicity and possibilities of integrating electrochromic materials in design. The ultimate goal is to inspire the puzzle to make use of electrochromic materials in their product designs, through exiting creativity and curiosity. When a puzzle piece is connected to the framework, a closed loop circuit is created between the voltage source and the coin cell battery, thus the puzzle piece will change its color. When the polarity is reversed (i.e. the puzzle piece is turned 180 degrees within the horizontal plane), it immediately switches from its primary EC layer to its secondary EC layer or vice versa. All primary EC layers will form the first puzzle to be created and all secondary EC layers the secondary puzzle. Meaning, ‘the puzzle of electrochromism’ is not just one puzzle, but includes two different puzzles. Besides the controlled color change, the other unique material properties it demonstrates are: low voltage operation, memory effect, simplicity and transparency. All individual puzzle pieces represent a different stacking sequence, through which the shape/pattern change (i.e. single and double image display), coloring (i.e. immediate and color flow), design of the images displayed (i.e. isolated and linked) and interaction between the two EC layers (i.e. overlap, connection and separation) are demonstrated. In the end, ‘the puzzle of electrochromism’ is a demonstrator making electrochromism easy understood, explainable and approachable for designers to use within their product designs; i.e. the aim of this thesis. On top of this, it is not only a good demonstrator but also a good puzzle according to the ten puzzle principles of Shell (2008).