[based on: 2010, et al 2011, Piqueras- et al 2011; media] Here we discuss multidisciplinary work on a senso-aesthetic theory of materials, studying and unraveling the interconnected nature of how we perceive the sensorial aspects of materials in relation to core physical properties.
We consider the definition of material from scientific and artistic perspectives, and describe how experiments undertaken by a multidisciplinary team within the Institute of Making worked to draw these sides together in a coherent and productive fashion.
The relationship between the objects created for studying the sound and taste of materials, and how their physical properties affect esthetic perception of the objects, will be introduced as an innovative methodology for investigating material-user interactions.
[Keywords: materials, objects, senso-aesthetic, sound, taste]
…The Taste Of Materials: Similar to the way we related the esthetic qualities of tuning forks to their underlying physical characteristics, we conducted an experiment to correlate taste characteristics of solid materials with their physical properties. The specific focus was on the differences in how “metallic” tasting a set of metal objects were in relation to well-defined physical variables. Tastes are received through taste buds on the tongue. There are 5 generally accepted basic tastes: bitter, salty, sour, sweet, and umami (2002). The perception of flavor and more general oral sensations are dependent on further factors such as smell, texture, and temperature (2001). The concept of taste is generally associated with substances that we place in the mouth in order to consume. However, the experience of taste in relation to inedible matter is much less appreciated and understood. Although “metallic” is not commonly considered a basic taste, there is growing evidence that metal ions act as chemosensory stimuli in the mouth: et al 2006 showed that ferrous sulfate produces a distinctly different sensation from the traditional basic taste descriptors, all of which are thought to have unique receptors ( et al 2006). The chemical aspects of the taste of inedible materials are commonly discussed in terms of their standard electrode potential, which defines the susceptibility of a particular material to being oxidized (1978). These potentials have been measured for most metals, and are believed to confirm broad trends of taste: metals that are highly susceptible to oxidization such as copper and aluminum have a noticeably metallic taste, whereas gold and silver are almost tasteless (Lawless et al 200618ya). However, previous to our work there had been no systematic investigation into the relation between the physical or chemical properties of solid materials and their taste.
…It was decided that preexisting teaspoons made from stainless steel would be coated in a number of different metals, and the final swatch is shown in Figure 4.2. 6 stainless steel teaspoons were electroplated with copper, gold, silver, tin, zinc, and chrome. Each metal was selected on the basis of its nontoxic status, suitability for contact with human skin and mucous membranes, its ability to be electroplated, and the ease with which it could be sterilized.
…We recruited 32 participants of mixed ages and both genders. Participants were blindfolded and asked to taste each spoon sequentially, rating each one on scales of 1–7 for the adjectives ‘cool’, ‘hard’, ‘salty’, ‘bitter’, ‘metallic’, ‘strong’, ‘sweet’, and ‘unpleasant’. The subjective experiential data were analyzed using standard statistical techniques. In brief, repeated measures one-way analysis of variance (ANOVA) with Tukey’s Multiple Comparison Test was performed.
…The Results: …For the adjective ‘metallic’, an inverse correlation between the electrode potentials of metal ions and perceived metallic taste of the metals was observed. An identical pattern was observed for the adjective ‘strong’. For this reason, zinc and copper were considered as strong tasting, while the other metals were considered mild tasting. A near-identical pattern was seen with the adjective ‘unpleasant’, with the minor exception that the difference between silver and either copper or zinc was not as statistically-significant: silver was not statistically-significantly more unpleasant than the other mild-tasting metals. None of the metals differed statistically-significantly in saltiness or sweetness. The experiment revealed that more negative standard electrode potentials correlated strongly with perceived tastes of solid metals described as metallic, bitter, and strong, with an inverse correlation. The zinc and copper spoons rated highest for bitter, metallic, and strong descriptors, while the gold and chrome rated as the most pleasant tasting spoons. When putting these spoons in the mouths, the participants often commented on how they liked them, or at least noted the absence of taste. Gold was determined to be the least strong tasting, followed closely by chrome, but chrome rated as being the least metallic, closely followed by gold. Finally, gold spoon emerged with the highest sweet rating of all the spoons.
It is commonly presumed that metallic tastes are unpleasant. In our taste study the descriptor metallic was statistically correlated with both the adjectives ‘unpleasant’ and ‘strong’, which indeed suggests that, when considering metal spoons, metallic taste is considered both strong and unpleasant. This raises the possibility that our measurements of metallic tastes, where gold and chrome were the least metallic, may correlate with preference for different metals, although this needs to be studied further.
[Should you get gold-plated spoons for ice cream? Maybe, especially for ice cream. I bought a gold-electroplated ‘demitasse’ coffee spoon for $9 and tried it out with my ice cream: my normal aluminum spoons have a definite slight ‘sour’ tang to them compared to the gold spoon, which just tastes neutral. Not sure if it’s worthwhile to try to get gold-plated utensils in general, but interesting that the taste difference does exist.]