Flexible radio frequency identification tags

A stretchable article comprising:

• a more stretchable first substrate;
• a less stretchable second substrate suspended from the first substrate from a finite number of attachment points;
• and
• an electronic circuit comprising an antenna disposed on the second substrate, such that when the article is stretched, the first substrate undergoes a greater in-plane strain than the second substrate and the electronic circuit, and the resonance frequency of the antenna is essentially the same as the resonance frequency of antenna when the article is in the unstretched state.

A stretchable radio frequency identification tag comprising:

• a flexible stretchable first substrate;
• a second substrate spaced apart from the first substrate and attached to the first substrate at a finite number of discrete attachment locations, the
• attachment locations defining an air gap between and substantially coextensive with the first and second substrates;
• an electronic circuit disposed on the second substrate;
• and
• an adhesive layer adhered to the first substrate, the adhesive layer defining an opening therein, the second substrate disposed within the opening.