As explained in the pre-eminent custard idea (link), dilatant mixtures are soft when left to their own, but become hard under pressure - the harder it's struck, the harder it is.
One problem with standard landmines is that they do tend to kill people, and thus are really only good for crowd control if you name is Pinochet or Ceausescu.
So why not use dilatant mines?
The dilatant in question would be soaked into cotton balls (thanks to [ldischler]) to maintain integrity.
When exploded, the dilatant mixture would be put under great pressure, in the form of...well, of an explosion.
The dilatant/cotton would be cast off, and would probably become liquid again in flight. But as those blobs strike a person or object, they'd (likely) take a moment to spread out and then resolidify, causing welts and bruises.
Shrapnel is easily prevented: Put the explosive and dilatant inside soft plastic baggies. The problem of burns is just as easily solved - perhaps use a nitrogen generator to create a high-pressure blast?
Added bonus: Cleanup is a breeze. Using an inert dilatant in the device means using a fire hose at the end of the day.
Side note: I'm not suggesting using custard here. There are bazillions of dilatant mixtures out there, and any one of them would be fine. So don't just fishbone me out of custardphobia - fishbone me because it's a stupid idea (or bread me for the opposite, whichever).-- shapu, Jan 05 2005 Custard Speed Bumps Custard-Filled_20Speed_20Bumps [shapu, Jan 05 2005] There's a dilettante mime joke in here waiting to explode.-- jurist, Jan 06 2005 I could be wrong but I think that the blobs of non-custard wouldn't be softened on impact, //the harder it's struck, the harder it is//, this is probably true of, the harder it strikes the harder it is. You'd just have yourself blobby shrapnel.-- 2 fries shy of a happy meal, Jan 06 2005 I'm basing my supposition of spreading on the idea that bullets spread out a bit when they hit something, too...and dilatants, even under high stress, probably remain softer than lead bullets.
Probably.-- shapu, Jan 06 2005 I'm for controlling crowds of dilettantes. Think of how easy it would be to get a good table in Manhattan!-- crater, Jan 06 2005 The problem, Shapu, is keeping ballistic custard in chunk form, because, even though it may stiffen during launch, it has very little tensile strength and will break up into a harmless mist. So, do what the aerospace people do: add fiber. Load your mines with goo saturated cotton balls.-- ldischler, Jan 06 2005 Noted. Updated. Thanked.-- shapu, Jan 06 2005 Send the dilettantes to La Guillotine on West Hollywood's Sunset Strip.-- mensmaximus, Jan 06 2005 Perhaps the solution may be to cup the liquid as you do in the game of Jai-Lai. By creating a spherical launching mechanism, or some other volumetric entity, you can limit the shear applied force on the entire projectile. It would be similar to throwing a snowball and not having it explode before it reaches its intended target. A catapult mechanism might be a possible launching device. In this manner, you could also control each piece instead of just throwing an explosive into the middle of everyone.-- Bosserrrrr, Jul 16 2005 random, halfbakery