Advances in liquid metals for biomedical applications

Abstract

To date, liquid metals have been widely applied in many fields such as electronics, mechanical engineering and energy. In the last decade, with a better understanding of the physicochemical properties such as low viscosity, good fluidity, high thermal/electrical conductivity and good biocompatibility, gallium and gallium-based low-melting-point (near or below physiological temperature) alloys have attracted considerable attention in bio-related applications. This tutorial review introduces the common performances of liquid metals, highlights their featured properties, as well as summarizes various state-of-the-art bio-applications involving carriers for drug delivery, molecular imaging, cancer therapy and biomedical devices. Challenges for the clinical translation of liquid metals are also discussed.

Ga‐Based Liquid Metal Micro/Nanoparticles: Recent Advances and Applications

“…The electronic configuration of post‐transition metals consists of completely filled d and partially filled p orbitals . These unpaired electrons in p orbitals can make covalent or metallic bonds, resulting in their high boiling points . Gallium has the lowest melting point (29.8 °C) in the post‐transition metal group, stemming from the weak binding between Ga atoms .…”

“…These unpaired electrons in p orbitals can make covalent or metallic bonds, resulting in their high boiling points . Gallium has the lowest melting point (29.8 °C) in the post‐transition metal group, stemming from the weak binding between Ga atoms . When gallium forms an alloy with other elements, such as In or Sn, its melting point is further reduced and controlled by the composition ratio, as shown in Figure a .…”

Liquid Metal–Based Soft Microfluidics

“…Microfluidics, which integrate functional fluids onto a chip‐like system with compact size and low energy consumption in a portable manner, show tremendous prospects in the field of drug/cell screening, sensing, health monitoring and microfabrication . Replacement of the traditional fluids by LM results in additional features to the system and shifts the applications away from biorelated fields to electronics and related fields . LM shows some unique advantages in LM‐based microfluidics.…”

Light‐Induced Shape Morphing of Liquid Metal Nanodroplets Enabled by Polydopamine Coating

“…This approach has been well‐studied and the resulting colloidal solution was employed as conductive ink for soft and flexible electronics . Stable aqueous suspensions of LM nanodroplets are not only for electronic applications, but also exhibit great potential in medicine and therapy, such as drug delivery, photothermal therapy, and bioimaging . Water‐soluble surfactants, including cetrimonium bromide, poly(4‐vinyl‐1‐methyl‐pyridinium bromide), lysozyme, and trithiocarbonate‐functionalized brushed polyethylene glycol have been used to stabilize LM nanodroplets during and after sonication of bulk LMs in water .…”