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Page 18 of 36 Chen et al. Soft Sci. 2026, 6, 9

small-volume MLMs tend to maintain a near-spherical droplet, stabilized by the balance between capillary
pressure and external forces.

MLM droplet-based soft robots exhibit unique advantages in advanced applications due to their combined
fluidic, metallic, and magnetic properties. The simultaneous presence of magnetic responsiveness and
fluidity allows precise spatial manipulation under magnetic fields while maintaining shape deformability .
[87]
Surface tension-dominated behavior at small scales ensures shape recovery after deformation, crucial for
adaptive and reconfigurable devices. Moreover, their low toxicity facilitates biomedical applications like
targeted drug delivery . Consequently, MLM droplet-based soft robots demonstrate significant potential for
[54]
applications in fluid manipulation, flexible electronics, and biomedical engineering.

The MLM droplet can achieve high-performance droplet manipulation through its unique active or passive
deformability and phase-transition capabilities. The MLM droplet robot can transport droplets across a wide
volume range (5-1,100 μL) at speeds up to 180 mm·s , adapt to confined spaces via fluidity-based shape
-1
modulation, and split or merge on demand for cooperative multi-droplet tasks. Its magnetic-field-induced
shape control enables tunable adhesion forces, while temperature-responsive solidification allows
stimuli-free droplet pinning [Figure 9A] . When integrated into microfluidic architectures, the MLM
[87]
droplet can function as a magnetically manipulated valve element by passing through and blocking the
microchannel, exhibiting 92% flow control efficiency at 1 mL·h -1[104] . In another work, Firouznia et al.
introduced a shapeshifting concept for the LM droplet, transforming its explosive electrohydrodynamic
instability under a magnetic field into a controlled, cyclic motion [Figure 9B] [105] . This approach creates a
compact, soft fluidic pump from a single droplet, positioning it as a novel on-board power source for soft
robotics and microfluidic devices .
[105]

Capitalizing on their dual conductive and deformable properties, MLM droplet-based robots demonstrate
unique potential for creating reconfigurable and flexible electronics. The MLM droplet can function as a
magnetically manipulated conductive switch by dynamically bridging or isolating electrodes as it passes
through surface-modified microfluidic channels without residual. Based on this mechanism, a soft
reconfigurable circulator was designed for soft robots to perform advanced functions, such as logic
computation, reprogrammability, and self-adaptivity [Figure 9C] [106] . In addition to mechanical switches,
Chen et al. developed the thermomagnetic LM switches by incorporating Ni Mn In Heusler alloy particles
0.6
1.4
2
into Galinstan, achieving fast bidirectional thermal response (1.2 s at 75 °C, reducible to 660 ms) for fire
safety applications .
[63]
Incorporating MLMs into conventional circuits and devices can significantly enhance their functionality.
The MLM droplet was encapsulated with highly conductive Ti C T (MXene) to avoid adhesion and
3
x
2
corrosivity during the integration. The MX-MLM (MXene-encapsulated MLM) was utilized as a top gate
electrode in a transistor to enable magneto-interactive synaptic functionality for detecting and learning 3D
path information [Figure 9D] . Similarly, the MLM droplet can also be coated with Cr 2 Te 3 to simultaneously
[89]
achieve nonwettability and electrical conductivity, enabling its application in high-density magnetic path
storage and as a flexible vibrator in wearable sensors for machine learning-enhanced dynamic gesture
recognition [107] . In addition, the MLM droplet can perform a larger deformation under a magnetic field,
functioning as a stretchable conductor capable of dynamically reconfiguring circuit pathways [Figure 9E] .
[89]
Moreover, under magnetic actuation, the aggregated magnetic microparticles induce MLM droplet
deformation into a continuous conductive trace on diverse substrates, enabling patterning of LM for flexible
electronics [Figure 9F] .
[46]