The fracturing and incorporation of liquid gallium surface oxides during shear mixing in air enables the stabilization of air bubbles within gallium which leads to the formation of a room-temperature liquid metal foam.

Thermoregulatory garments composed of liquid‐cooled plastic tubes have users ranging from astronauts to multiple sclerosis patients and are emerging as a flexible cooling solution for wearable electronics and high‐power robotics. Despite the plethora of applications, the current cooling systems are cumbersome to use due to their excessive size. In this work this issue is resolved by developing soft, thermally conductive silicone–aluminum composite tubes. To achieve optimal device performance, the material must be designed to balance the decrease in bulk thermal resistance and the increase in interfacial tube‐substrate resistance due to composite stiffening. Thus, to enable the rational design of such tubes, a closed form thermomechanical model that predicts cooling performance as a function of tube geometry and filler fraction is developed and experimentally validated. Predictions via this model and experiments are used to reveal how the tube's geometrical and material design can be adjusted to minimize the required length of tubing and maximize the heat extracted from a metallic surface and skin. Lastly, through a holistic analysis, this work demonstrates that besides significantly increasing overall cooling capability, the use of low‐resistance tubing can provide a multifold reduction in the cooling system size and enable novel operating modes.

The occasional use of chemical warfare agents (CWAs) by rogue states in current conflicts provides a reminder that these hazards are a real threat. Although hazmat suits made of fully impermeable barrier materials provide an effective means of protecting against CWAs, they also inhibit evaporative cooling which can cause rapid hyperthermia. This conundrum has motivated a search for novel materials that allow water vapor but not CWA permeation. Here we show that, at least for aerosolized CWA, this can also be achieved using a highly breathable composite fabric that self-seals only when exposed to target chemicals. Our approach is based on the use of selectively superabsorbing polymer (SAP) microbeads that are dispersed on a highly breathable fabric. Many CWAs, especially nerve and blistering agents, have low vapor pressure and can only be dispersed as a “fog” from aerosolization. We show that upon contact with an example organic aerosol (o-xylene) the proposed SAP microbeads dispersed on a nylon mesh swell highly, seal pores, and inhibit passage of the microdroplets. In contrast, in normal conditions the SAP microbeads do not absorb or swell upon contact with water and provide over 10 kg m–2 day–1 water permeation rate that is comparable to a cotton shirt.