It was pure coincidence that the Robot fabric I had ordered coordinated perfectly with the birthday t-shirt! Yay!
The pants are pretty basic - a pattern traced from a pair of Levi's long shorts, or short pants, whichever way you wanna slice it.
I added pockets on the bum out of the circuit board fabric, and added cuffs in the contrasting orange robot fabric. All 3 fabrics are from Robert Kaufman's Robot Factory collection.
The waist is just a simple elastic waist band. I always use ribbed non-roll waistband elastic.
Of course, little brother had to have a tee to celebrate the occasion too!
*Tie T-shirt material is the orange Robot Factory