This sounds similar to HP's $100k+ solution. There's another similar attempt I've read about recently. It's a form of stereolithography resin printing.
Instead of multiple needles in a granular material it's using multiple fast-aiming lasers pointing into a tank of UV-setting resin. The lasers shoot through a tank of translucent resin from multiple angles and where he beams intersect there's enough energy to set the resin without setting the surrounding bulk of it. A bigger array of lasers means more points can be set at once.
Normal SLA/DLP resin 3D printers already work a plane at a time, drawing up through a tank and having lasers hit that layer right at the surface. A bigger array of lasers means each layer gets set faster up to the limit of the resin's minimum cure time.
Most professional and some high end hobby 3D printers aren't FFD/FMD any longer. Resin, metal sintering, and other alternatives are leaving fused filament to the hobbyists. There's no reason sintering couldn't use more lasers, speeding things up to a practical limit of the metal's time to cool.
Personally, although it's still mostly hobbyist size and speed, I just recently backed a ceramic extrusion printer. It can use a variety of cheap and readily available materials to create heat-resistant, durable, food-safe items. Items can be smoothed and some details added before firing.
For your solution, have you considered a two-part epoxy as an alternate to granules and glues for finer resolution?