Viewpoints

About This Technology

Smart materials produce direct, inherent physical responses to signals such as temperature, voltage, pressure, magnetic fields, light, and so on. Though the mechanical behavior of an SM actuator often is unimpressive in isolation, the ability to use a very simple device to produce specific mechanical action in response to specific conditions or signals can dramatically improve the overall performance of a device. Designers can use SMs to simplify products, add features, improve performance, or increase reliability with relatively little mechanical complexity.

Most SM markets and technologies are young and remain largely unexplored (piezoelectric materials are a notable exception), with only a few simple, derivative products on the market. Fortunate combinations of technology and market conditions can bring explosive growth in commercial activity, however, as medical applications of shape-memory alloys have shown in recent years. Most SM technologies will slowly enter the market as suppliers and technologies mature and as users gain familiarity with the materials. Several SM technologies have just begun to enter or approach the market, and might find strong early sales in a few niches. Rapid advances in electronic control technology will continue to reduce the cost and increase the benefits of SM use. Existing SM applications are surprisingly numerous and diverse. Examples include simple piezoelectric speakers, card-eject mechanisms for laptop computers, tip positioners on scanning microscopes, self-expanding stents to hold coronary arteries open after angioplasty, a snow ski that actively damps harmful vibration frequencies, self-dimming automobile mirrors, medical imaging devices, autofocus motors for cameras, active noise control for electric transformers, and electronically controlled resistance units for home exercise equipment.

Development of SM fields will benefit companies that use SM components to add value to products and services, companies skilled in using SMs to design new products and services, and materials processors that add value to raw materials. The small volumes of SM consumption likely will have little impact on raw materials suppliers. Near-term returns on investments by SM suppliers generally will be modest, because most SM fields still are building infrastructure and knowledge bases for efficient and effective production, marketing, and use of SMs. The specialized knowledge necessary to produce SMs and to incorporate them effectively into products will slow the spread of SM use, but it also has led to high market valuations for companies developing products for high-value applications. Smart structures, which fully integrate structural and mechatronic components, represent the most refined use of SMs and might eventually enjoy very large SM markets. Only a very simple SM-based smart-structure product is in commercial use today. Other important areas of opportunity include applications in which designers desire performance improvements or new features but are unwilling to accept the compromises necessary to use conventional mechanisms and products (including nonmechanical devices) that must operate in a variety of conditions but have rigid designs optimized for a single operating point. Though improvements in SM performance would increase the range of possible applications, the major barriers to widespread SM use are users' lack of familiarity, the need for low-cost, robust production processes, and the need for improved design tools to enable nonexperts to use the materials with confidence.