c18 smart grenades

She held out her hand again, and this time received some smart grenades. They were small—she could fit four in her hand—but potent. There was no pin to pull; instead they primed on mental command, and detonated a specified time after leaving an infantryman's hand. They could also be detonated on command, but the reliability of that depended on alien interference, which made it often useless.

Given the alien propensity for shielding, they were designed to blast out a wave of secondary explosive pellets that detonated on contact, reshaping themselves to take advantage of the Munroe effect for armor penetration. In the last stages of detonation, a series of monoatomically‐edged shrapnel pieces were hurtled through what was hopefully a breach in the armor, carrying aggressive nanites intended to wreak havoc on a soft interior. Besides being generally effective against armored targets—which was practically everything above a certain mass—they were also good against alien forcefields which, in many ways, behaved like armor. In that case, there was a reasonable chance of temporary forcefield failure, though the shrapnel nanites usually failed to do more than superficial damage to the armor below the forcefield. At very close range, there was an excellent chance of forcefield failure.

An intricately crafted weapon that was, sad to say, reverse engineered from the aliens.

(To The Stars, Chapter 18)