Mechatronics and sfumato Connecting the dots through time

June 1, 2007
What could a 500-year-old painting technique have in common with a 21st century interdisciplinary design philosophy? Depending on how you look at it,

What could a 500-year-old painting technique have in common with a 21st century interdisciplinary design philosophy? Depending on how you look at it, almost everything.

Sfumato is an Italian word that means vanish, as in wisps of smoke (fumo) or vapor dissipating in air. The term also applies to a painting technique developed in the 16th century by the great artist and engineer, Leonardo da Vinci. The unusual method, which created an effect that da Vinci described as “without lines and borders, beyond the focus plane,” achieves extraordinary depth and softness, portraying images as if they are sitting behind a misty veil.

Da Vinci demonstrates his mastery of the sfumato technique no more convincingly than in the Mona Lisa. There, he brings his subject to life, not with brush strokes, but rather a three-dimensional array or matrix of translucent dots applied one at a time, layer upon layer, using needlelike tools. The almost holographic medium he composed rises some 30 layers above the working substrate, in some places — the eyes, for example — incorporating as many as 40 uniformly spaced dots per square millimeter.

Even more incredible than the technique, however, is the intent with which da Vinci applied it. In the Mona Lisa, da Vinci captured something uniquely human. He captured a smile that, in one sense, hides its true meaning, and in another, appears to be whatever the observer wants to see. An ordinary brush, even in da Vinci's hand, could not have rendered what he achieved with his elaborate system of dots.

In like manner, engineers today are achieving extraordinary results using an unconventional (interdisciplinary) design technique known as mechatronics. Like sfumato, the mechatronic technique is based on the collective function of many things working together — hierarchically, layer upon layer. By combining mechanical, electrical, and computer technology, machine designers are doing what would otherwise be impossible using a strictly mechanical or electronic solution, or even one where multiple disciplines are applied in isolation.

Another point of similarity is that the power of mechatronics, like sfumato, lies primarily in the intent of the designer and in the context of the design. Consider the common camshaft and its role in valve timing in an internal combustion engine. The shape and relative position of the cam lobes along the shaft rigidly determine when and how the valves open and close. Ask any camshaft to vary its timing pattern, however, and the limitations become immediately apparent.

Mechatronics trumps conventional design and its inherent limitations because it focuses on the end rather than the means. It also includes the element of programmability. In rendering a camshaft, the mechatronic approach would more than likely find an alternate route to valve timing. It would combine the functions of a microprocessor, an array of actuators and sensors, and a mechanical framework. It would offer unlimited variability, real-time adaptive control, and a scalable solution that could be used elsewhere.

As technology continues to evolve, tomorrow's interdisciplinary da Vincis will find a way to eliminate even the valves. Given capable fuel cells or some other alternative power source, they will render practical electric vehicles and many other machines that, today, no one would believe possible.

They say time repeats itself. In the case of sfumato and mechatronics, it certainly seems so.

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