Patterning of liquid metal (LM) is usually an integral step toward its practical applications. However, the high surface tension along with surface oxide makes direct patterning of LM very challenging. Existing LM patterning techniques are designed for limited types of planar substrates, which require multiple-step operation, delicate molds and masks, and expensive equipment. In this work, a simple, versatile, and equipment-free approach for direct patterning of LM on various substrates using magnetic field is reported. To achieve this, magnetic microparticles are dispersed into LM by stirring. When a moving magnetic field is applied to the LM droplet, the aggregated magnetic microparticles deform the droplet to a continuous line. In addition, this approach is also applicable to supermetallophobic substrates since the applied magnetic field significantly enhances the contact between LM and substrate. Moreover, remote manipulation of the magnetic microparticles allows direct patterning of LM on nonplanar surfaces, even in a narrow and near closed space, which is impossible for the existing techniques. A few applications are also demonstrated using the proposed technique for flexible electronics and wearable sensors.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201901370. used for the other liquids. Therefore, it is challenging to directly pattern LM using some well-established printing strategies such as inkjet or screen printing.Various LM patterning techniques have been developed in the past few years based on microfluidic injection, [11] selective wetting, [2d,12] LM suspensions printing, [13] stencil lithography, [14] reductive printing, [15] imprint lithography, [16] selective mechanical sintering, [17] laser patterning, [18] microcontact printing, [19] and three-dimensional (3D) printing. [20] However, the reported techniques involved multiple-step operation, additional pretreatment of substrate, post sintering, delicate molds and masks, tedious microfabrication process, as well as sophisticated equipment. These not only complicated the fabrication but also increased the cost. Besides, each of these reported techniques was designed for a specific substrate, which limited the widespread applications of LM. Due to low adhesion, it is rather difficult to directly pattern LM or transfer the existing LM patterns onto supermetallophobic substrates, on which the contact angle of an LM droplet exceed 150°. In addition, most existing patterning techniques were limited to planar substrates. 3D patterning of LM remains rather challenging, which involved sophisticated facilities (e.g., pressure pump, translation stage) and additional encapsulation and fixation steps for practical applications. [20a] Thus, developing a simple, versatile, and equipment-free LM patterning technique for various planar and nonplanar substrates is highly desired to broaden the applications of LM.It has been reported that magnetic actuation can be used for LM manipu...

concentrations are incompatible with the physiological conditions, as the diffused ions may irritate biological tissues. [1c] It is also challenging to pattern ionic conductors with a high resolution because of the inevitable diffusion. [15] Conducting polymers such as poly(3,4-ethylene dioxythiophene) (PEDOT) possess relatively low conductivity, [16] while solid metallic conductors demonstrate remarkable mechanical mismatch with soft hydrogels. Although conductive nanocomposites like metal nanowires offer good conductivity and stretchability, the required synthesis is complicated and costly. Metal nanowires also have poor biocompatibility and can cause adverse health effects. [17] Last but not least, the adhesion of conductive components on hydrogel surfaces is still a problem to be addressed. [18] Hence, for practical applications, most conductors must be dispersed into the hydrogel matrix, making it difficult to form functional structures on the hydrogels. Ga-based alloys as room temperature liquid metals (LMs) are a unique type of material possessing high conductivity, fluidity, deformability, nontoxicity, and self-healing capability. [19] These properties make them ideal conductors for flexible and stretchable hydrogel electronics. [20] However, the lack of efficient patterning techniques hinders the realization of functional LMbased hydrogel electronics. Although numerous techniques have been developed for the patterning of LM, they are generally designed for dry and rigid substrates. [21] These patterning techniques have always involved the pretreatment of substrates to increase adhesion to LM, or use of mechanical force for postsintering. Therefore, these techniques cannot be readily applied to wet and delicate hydrogels. Although previous work has shown that it is possible to form helical LM structures in the hydrogel by microfluidic injection, discrete and complex LM patterns are still difficult to obtain due to the need for inlets and outlets of the microfluidic system. [22] Therefore, it is highly desirable to develop a new method for the patterning of LM on hydrogels for practical applications. We have previously developed a versatile LM patterning technique using a magnetic field. The LM droplets dispersed with magnetic microparticles can be patterned on various substrates simply by moving a magnet. [23] Despite its simplicity, it is still challenging to obtain high-resolution LM patterns using this technique. In this work, high-resolution patterning of LM on hydrogels is accomplished by in situ fabrication of a shadow Soft, wet, and biocompatible hydrogels have emerged as promising materials for flexible and stretchable electronics owing to their similar properties with biological tissues. However, most existing conductive materials used for hydrogel-based electronics have drawbacks such as poor biocompatibility, low conductivity, and/or high mechanical mismatch with soft hydrogels. In this work, direct patterning of nontoxic and highly conductive liquid metal (LM) on hydrogels is reported for soft...

Soft actuators with perception capability are essential for robots to intelligently interact with humans and the environment. However, existing perceptive soft actuators require complex integration and coupling between the discrete functional units to achieve autonomy. Here, we report entirely soft actuators with embodied sensing, actuation, and control at the single-unit level. This is achieved by synergistically harnessing the mechanosensing and electrothermal properties of liquid metal (LM) to actuate the thermally responsive liquid crystal elastomer (LCE). We create multifunctional LM circuits on the LCE surface using a simple and facile methodology based on magnetic printing. The fluidic LM circuit can not only be utilized as a conformable resistive heater but also as a sensory skin to perceive its own deformation. Moreover, the rational design of the LM circuits makes it possible to achieve biomimetic autonomous actuation in response to mechanical stimuli such as pressure or strain. In addition, the intrinsic stretchability of LM allows us to create 3D spring-like actuators via a simple prestretch step, and complex helical motions can be obtained upon mechanical stimulation. This work provides a unique and simple design for autonomous soft robotics with embodied intelligence.

Exosomal proteins are emerging as relevant diagnostic and prognostic biomarkers for cancer. This study was aimed at illustrating the clinical significance of exosomal Copine III (CPNE3) purified from the plasma of colorectal cancer (CRC) patients. The CPNE3 expression levels in CRC tissues were analyzed by real-time PCR, western blot, and immunohistochemistry. Plasma exosomes were isolated to examine the CPNE3 level using ELISA. Pearson's correlation analysis was performed to investigate the CPNE3 levels between CRC tissues and matched plasma samples. Receiver operating characteristic curve analysis was developed to measure the diagnostic performance of exosomal CPNE3. The Kaplan-Meier method and Cox's proportional hazards model were utilized to determine statistical differences in survival times. CPNE3 showed increased expressions in the CRC tissues. A moderately significant correlation was found between CPNE3 expression in CRC tissues by immunohistochemistry and matched serum exosomal CPNE3 expression by ELISA (r = 0.645,(r = 0.645, p < 0.001). < 0.001). Exosomal CPNE3 yielded a sensitivity of 67.5% and a specificity of 84.4% in CRC at the cutoff value of 0.143 pg per 1ug1 ug exosome. Combined data from carcinoembryonic antigen and exosomal CPNE3 achieved 84.8% sensitivity and 81.2% specificity as a diagnostic tool. CRC patients with lower exosomal CPNE3 levels had substantially better disease-free survival (hazard ratio [HR], 2.9; 95% confidence interval [CI]: 1.3-6.4; p = 0.009) = 0.009) and overall survival (HR, 3.4; 95% CI: 1.2-9.9; p = 0.026) = 0.026) compared with those with higher exosomal CPNE3 levels. Exosomal CPNE3 show potential implications in CRC diagnosis and prognosis.

Metastasis is one of the most important factors that lead to poor prognosis in cancer patients, and effective suppression of the growth of primary cancer cells in a metastatic site is paramount in averting cancer progression. However, there is a lack of biomimetic three-dimensional (3D) in vitro models that can closely mimic the continuous growth of metastatic cancer cells in an organ-specific extracellular microenvironment (ECM) for assessing effective therapeutic strategies.Methods: In this metastatic tumor progression model, kidney cancer cells (Caki-1) and hepatocytes (i.e., HepLL cells) were co-cultured at an increasing ratio from 1:9 to 9:1 in a decellularized liver matrix (DLM)/gelatin methacryloyl (GelMA)-based biomimetic liver microtissue in a microfluidic device.Results: Via this model, we successfully demonstrated a linear anti-cancer relationship between the concentration of anti-cancer drug 5-Fluorouracil (5-FU) and the percentage of Caki-1 cells in the co-culture system (R2 = 0.89). Furthermore, the Poly(lactide-co-glycolide) (PLGA)-poly(ethylene glycol) (PEG)-based delivery system showed superior efficacy to free 5-FU in killing Caki-1 cells.Conclusions: In this study, we present a novel 3D metastasis-on-a-chip model mimicking the progression of kidney cancer cells metastasized to the liver for predicting treatment efficacy. Taken together, our study proved that the tumor progression model based on metastasis-on-a-chip with organ-specific ECM would provide a valuable tool for rapidly assessing treatment regimens and developing new chemotherapeutic agents.