Fibers and textiles date back to the beginning of civilization itself, yet remarkably, the fundamental properties of these materials have remained largely unchanged for millennia. By and large, natural fibers such as cotton and wool, and synthetic fibers such as nylon and polyester form the foundation for the vast majority of textile products, yet functionally, these materials are relatively simple.

As such, humans continue to expect traditional features from their textile-based products, primarily used for protection, aesthetic, and cultural purposes. In the early 2000s, a fundamental shift in fiber technology occurred – a new class of fibers were invented, dubbed multi-material fibers[1]. Invented by MIT scientists in 2000, and subsequently spread throughout laboratories across the world over the past couple of decades, this new class of fibers enables the integration of disparate materials, including semiconductors, metals and insulators within a fiber form factor.

The ability to broaden the scope of materials processable into fibers has given rise to drastically new fiber functionalities, including fibers that can sense and actuate, store energy, change color, emit and detect light, store data, communicate, and more[1-6]. As a result, new textile-based applications emerged with increasingly sophisticated functions, such as fabrics with embedded sensors for healthcare, climate-adaptive textiles for self-regulated cooling, soft fabric light emitting displays and more.

This article provides a high-level summary of the foundational multi-material fiber technology and manufacturing methodology, the integration of these novel fibers into textiles, and an overview of some of the emerging applications. The work reported on here is primarily carried out by Advanced Functional Fabrics of America (AFFOA) is part of the Manufacturing USA Network, a collection of over 150 organizations working to advance the manufacturability and commercialization of functional fibers and fabrics in the US.