Absolutely. Every single trend is a sigmoid function. However, Kurzweil at the very least (and this comes from a site maintained by his people) believes that it is less a single function so much as it is the aggregate of an increasing number of sigmoid functions that are interacting with each other.
More precisely, if you do a detailed analysis of many critical trends you find out something very important. Not only are the growth functions exponential, but the exponents of the system themselves are increasing. I am in open disagreement with Kurzweil on many issues, but the trend analysis is correct. It doesn't matter that the trends are sigmoid because there is an overarching exponential function that these sigmoid functions are a part of.
The final analysis is sigmoidal, but not precisely how you are imagining it. The inflection point of the "super-curve" is sufficiently deep technologically that it represents a fundamentally different existence.