Activatable sensor platforms having indicators for activation verification

An activatable environmental indicator, comprising:

• a substrate, and
• a plurality of microcapsules supported by the substrate,
• the activatable environmental indicator having a non-activated configuration that is unresponsive to a predetermined environmental stimulus, an activated configuration that is responsive to the predetermined environmental stimulus, and an exposed configuration after responding to the predetermined environmental stimulus;
• at least a subset of the plurality of microcapsules release an environmental indicator material in response to an activation event that transitions the activatable environmental indicator from the non-activated configuration to the activated configuration,
• the activatable environmental indicator is responsive to the predetermined environmental stimulus after the activation event and transitions from the activated configuration to the exposed configuration in response to exposure to the predetermined environmental stimulus, and
• the activatable environmental indicator includes a first visual indicator when the activatable indicator is in the non-activated configuration, a second visual indicator when the activatable indicator is in the activated configuration, and a third visual indicator when the activatable indicator is in the exposed configuration.