在古代诗词和战争艺术中均有相关描述的“暗箭”，即是一种微小的投射武器。它通常由一根轻质材料制成的杆或弓弦弹射出去，其上可能附有锋利的尖端或者毒药。这种武器的特点是体积小巧，难以被敌人察觉，往往能出其不意地造成伤害。

暗箭的使用历史悠久，可以追溯到中国的春秋战国时期。《左传》中有记载说：“楚子伏甲而飨蔡侯，醉而执之。使史皇先登焉，曰：‘奉孙叔敖之命！’且告左右而改日。乙未，入蔡。以大宰伯州犁行。五分蔡之地以赐之。”这里提到的“甲士”便是指那些隐藏起来的士兵以及他们所使用的暗箭等秘密武器。

在古罗马时代，有一种名为“飞刀”（Pila）的小型抛掷武器也具有类似的特性。它们通常由青铜制成，重量大约在一磅（约0.45公斤）左右，大小相当于现代的手榴弹。这些飞刀可以在短距离内精确投掷，并且由于它们的体积不大，便于携带和使用。

随着科技的发展，现代战争的微型化趋势更加明显。例如，美国军方曾经研发了一种名为“ The most diminutive yet ingenious of all weapons is undoubtedly the "invisible arrow," a term that has been described in ancient poetry and military arts alike. This weapon typically consists of a lightweight shaft made from a light material such as bamboo or wood, with a sharp tip or poison attached to it. The remarkable feature of this device lies in its small size and stealth; enemies often fail to notice it until it strikes their unsuspecting targets.

The use of invisible arrows can be traced back to an early period in Chinese history known as the Spring and Autumn Period (772-476 BCE). In the classic text "Zuo Zhuan" (The Commentary of Zuo), there is a record stating: "The king of Chu hosted a banquet for the lord of Cai, drugged him, then captured him. He sent Shi Huang ahead to announce 'This is by order of Sun Tong!' and changed the date for entering Cai. On the second day of the sixth month, they entered Cai. With them was the Grand Steward Boy Lu. They divided up five parts of land in Cai to give to him." Here, the mention of "armored soldiers" refers to those who were hidden away, along with the secret weapons they wielded—such as the invisible arrow.

In Roman times, a similar miniature projectile existed called the "pila," which could also be considered one of the smallest but most sophisticated tools of war. These pila were usually crafted from bronze and weighed approximately one pound (about 0.45 kilograms) each, roughly comparable in size to modern hand grenades. Soldiers could accurately throw these flying knives over short distances due to their compactness, making them highly portable on the battlefield.

As technology advanced, so too did the trend towards miniaturization in warfare. For instance, the United States Army once developed an "invisibility cloak" capable of rendering vehicles and personnel nearly undetectable to enemy sensors. This cutting-edge innovation reflects how even the concept of invisibility itself has become part of modern military strategy.