Squid games: a breakthrough in electronic-free displays

This electronic-free system uses magnetic fields to create flexible displays that can securely show and hide information.

Mimicking squid communication

Squids can rapidly change the colour of their skin by contracting and expanding muscles around pigment-filled cells. The research team has developed a similar system using tiny particles, called Magnetoactive Janus Particles (MAJPs). Each particle has two sides – one light and one dark. By applying magnetic fields, these particles flip between their states, just like a squid changing colours to send messages.

These particles are embedded in a soft, flexible material. The particles' rotation is controlled by magnets, allowing the display to either show or hide specific information, depending on the magnetic field applied.

Secure displays: no electronics required

One of the most impressive features of this new display technology is that it functions without any electronics. This makes it ideal for use in places where power or light sources are either unavailable or inconvenient. For example, these displays could be used in wearable devices, clothing, ID badges, or smart barcodes that reveal information only when placed near a specific magnet.

When placed near a simple magnet, the screen shows an image anyone can see. However, when exposed to a more complex magnetic array, it reveals a private, encrypted image. This magnetic encryption works like a lock-and-key system, where only the correct magnetic pattern can unlock the hidden information. Because it doesn’t rely on electronic components, the display is also more secure, making it harder to hack.

Flexible, programmable, and safe

As well as being safe from hacking, the display is highly versatile. It is lightweight and flexible, meaning it can be wrapped around a wrist, integrated into clothing, or used as a sticker. The technology is portable and does not need a power source to function, making it a practical alternative to traditional displays, which can be vulnerable to power issues.

The system is programmable, allowing researchers to encode specific information that will only appear when exposed to the right magnetic field. Once programmed, the device acts like a secure, non-hackable storage system for visual information. This makes it especially useful for applications like smart ID badges, barcodes, or other devices where privacy is important.

Magnetic pixels and encryption

The particles in the display act like the pixels on a screen. Each particle has a light and dark side. When a magnetic field is applied, the particles align to form an image. This works much like how a squid changes its skin colour by controlling pigment cells.

What makes this system useful is its ability to display both public and private information. A simple magnetic field shows a public image, but a more complex magnetic key is needed to unlock private, encrypted information. The encryption is highly secure because it’s purely physical – there’s no software or code to hack. The magnets themselves act as the tools to encrypt and decrypt information.

Etch-a-sketch but smarter

The display has a clever feature that works a bit like an Etch-a-Sketch toy. If the display is shaken, the image disappears. However, unlike the toy, the information isn’t lost forever. The magnetic particles keep the image stored and will show it again when exposed to the correct magnetic field. This means the display can be ‘erased’ and ‘reset’ without losing any data, making it useful for dynamic information displays.

The research team also plans to expand this technology, using different pigments to create colour-changing surfaces, potentially for use in robotics or camouflage.

A sustainable future for secure displays

This squid-inspired technology offers a more sustainable way to display information. Because it doesn’t rely on electronics or backlighting, the display consumes very little energy, relying instead on ambient light for visibility. This makes it more energy-efficient than traditional displays.

Additionally, the flexible, durable nature of the display means it can withstand physical stress, making it last longer and reducing the need for frequent replacements. The ability to erase and reprogram information without losing data adds another layer of sustainability, as the components can be reused repeatedly.

The future of secure displays

As concerns over hacking and data privacy grow, the shift to physical, analogue encryption systems is becoming increasingly relevant. This squid-inspired technology offers a fresh approach by eliminating the need for electronics and relying instead on a simple, yet powerful, magnetic encryption system.

Because it is soft, flexible, and resilient, the display can withstand physical wear and tear, making it ideal for environments where electronics might fail. The applications range from smart clothing to secure barcodes, and even beyond, into military camouflage or interactive wearables.

The beauty of this innovation lies in its simplicity. It mimics a natural system, using magnetic fields to manipulate particles in much the same way a squid’s skin uses pigments to communicate. The result is a highly secure, flexible, and electronic-free display that could transform how we think about information storage and encryption in the future.