This post is intended as a request for advice.

I have an ongoing project to develop interactive, Internet-based lessons for K-12 classrooms.

Home Page
Examples page (with links to demo lessons)

A former teacher with no graphic design experience, I have learned various web skills to assemble these lessons (that have now been used by many students in four separate states). Clicking through the second link above one finds two demo lessons, with links to animations at page bottom - and in the case of the "Protozoa" lesson, animations embedded directly in the lesson pages.

These lessons are based on Nat'l standards and are written at grade-level readability. Students view a lesson, complete a short quiz that is scored automatically (cgi), and feedback is displayed immediately with results being uploaded to server for review by the teacher (grouped into classes, complete with item analysis - "26% answered #3 incorrectly", etc.). My own illustrations/animations, however, are quite flat.

Feedback from participating teachers is extremely encouraging ("When will there me more lessons?"). Believing that the format is somewhat unique, I would like to invite graphic artists with some experience to visit the site and see the potential value of such a project; perhaps see an opportunity to help build the sort of lessons I looked for on the WWW as a teacher and never found.

Several teachers (content writers), even a couple of animators, have offered to contribute. But, responses so far from artists, through PMs at sites like HOWdesign, have not been encouraging.

With a budget of $0.00, I wonder: How best might I approach such an "invitation to participate"? Thoughtful responses only, please.