Hard to see how that's worth more than $50m, even if you think their R&D pipeline is solid (and maybe it isn't). That means STEM should be worth something like $2.5m (5% of $50m), not accounting for likely dilution post-merger/post-revers-split. $2.5m divided by 11.7m shares is $0.21 per share.
By my reckoning, STEM should be worth between $0.01 and $0.50 per share based on the available facts about this merger, depending on your assumptions about Microbot's current value and the amount of dilution coming down the pike.