Well, it´s not about droids (or that much about technology), but what about making him a botanist? There are a few possibilites that sprang in my mind:
1. In MedStar novels (M.Reaves), the Seps and Reps fought after bota, a plant that had unique properties, different for each species, ranging from recreational drug to cure-all. By the end of the book, the plant suffered a genetic shift that made it useless. So the scientist could be trying to reverse the process and restore the effective healing genes?
Such a thing would be very valuable. Any number of criminal syndicates would want to get its hands on it, and sell it for humongous profit. Or regular pharmaceutical companies might want to stop the work to ensure that nothing will cut into their profit.
2. The scientist could be working to create a durable, fast-spreading type of grass that would help terraform barren planets. Something that would take grip on almost anything, survive in any atmosphere and quickly multiply, which would allow for a fast creation of oxygene-rich atmosphere, where other species of both flora and fauna might survive.
Such a thing could be valuable, allowign habitation of planets that were impossible, or too costly. But it could be easily used as a bioweapon, driving out local flora of habitable worlds and disrupting its ecosystem, or even used as base for some toxic form (like the Kholm-grass used by the Empire on Honoghr). I admit, I don´t have this very tought through, but it is a start.