A flexible glucose biosensor modified by reduced-swelling and conductive zwitterionic hydrogel enzyme membrane.

This paper reports a flexible glucose biosensor which is modified by a reduced-swelling and conductive zwitterionic hydrogel enzyme membrane that contains two forms of chemical cross-links. One chemical cross-linking is induced by thermal initiators and forms the basal network of the hydrogel. Another cross-linking is achieved by the coordination interactions between the multivalent metal ion Al and anionic group -COO of zwitterionic poly-carboxy betaine (pCBMA), which significantly increase the cross-linking density of the zwitterionic hydrogel, improving the reduced-swelling property and reducing the pore size.

Extended-depth-of-field imaging with an ultra-thin folded lens.

Optical systems with extended depth of field (EDOF) are crucial for observation and measurement applications, where achieving compactness and a substantial depth of field (DOF) presents a considerable challenge with conventional optical elements. In this paper, we propose an innovative solution for the miniaturization of EDOF imaging systems by introducing an ultra-thin annular folded lens (AFL). To validate the practical feasibility of the theory, we design an annular four-folded lens with an effective focal length of 80.

Deep-learning enabled smart insole system aiming for multifunctional foot-healthcare applications.

Real-time foot pressure monitoring using wearable smart systems, with comprehensive foot health monitoring and analysis, can enhance quality of life and prevent foot-related diseases. However, traditional smart insole solutions that rely on basic data analysis methods of manual feature extraction are limited to real-time plantar pressure mapping and gait analysis, failing to meet the diverse needs of users for comprehensive foot healthcare. To address this, we propose a deep learning-enabled smart insole system comprising a plantar pressure sensing insole, portable circuit board, deep learning and data analysis blocks, and software interface.

A wearable microfluidic system for efficient sweat collection and real-time detection.

Sweat is an important biofluid with rich physiological information that can evaluate human health condition. Wearable sweat sensors have received widespread attention in recent years due to the benefits of non-invasive, continuous, and real-time monitoring. Currently, an efficient device integrating sweat collection and detection is still needed.

Exploring viscosity influence mechanisms on coating removal: Insights from single cavitation bubble behaviours in low-frequency ultrasonic settings.

The role of acoustic cavitation in various surface cleaning disciplines is important. However, the physical mechanisms underlying acoustic cavitation-induced surface cleansing are poorly understood. This is due to the combination of microscopic and ultrashort timescales associated with the dynamics of acoustic cavitation bubbles.

A dual-mode fiber-shaped flexible capacitive strain sensor fabricated by direct ink writing technology for wearable and implantable health monitoring applications.

Flexible fiber-shaped strain sensors show tremendous potential in wearable health monitoring and human‒machine interactions due to their compatibility with everyday clothing. However, the conductive and sensitive materials generated by traditional manufacturing methods to fabricate fiber-shaped strain sensors, including sequential coating and solution extrusion, exhibit limited stretchability, resulting in a limited stretch range and potential interface delamination. To address this issue, we fabricate a fiber-shaped flexible capacitive strain sensor (FSFCSS) by direct ink writing technology.

Mechanistic study of ultrasound and microbubble enhanced cancer therapy in a 3D vascularized microfluidic cancer model.

Accumulating evidence has shown that ultrasound exposure combined with microbubbles can enhance cancer therapy. However, the underlying mechanisms at the tissue level have not been fully understood yet. The conventional cell culture in vitro lacks complex structure and interaction, while animal studies cannot provide micron-scale dynamic information.

Mechanisms underlying the influence of skin properties on a single cavitation bubble in low-frequency sonophoresis.

As a safe and effective method for systemic transdermal drug delivery (TDD), sonophoresis has drawn much attention from researchers. Despite numerous studies confirming cavitation as the main reason for sonophoresis, the effect skin has on cavitation bubble dynamics remains elusive due to the difficulty of experimental challenges. For a start, we reveal how single cavitation bubble (SCB) dynamics are affected by skin properties, including elasticity, hydrophilicity and texture.

An inkjet-printed bendable antenna for wearable electronics.

104Flexible antennas, which can conform to the skin and transfer signals to terminals, are particularly useful for wearable electronics. Bending, which frequently occurs to flexible devices, significantly affects the performance of flexible antennas. Inkjet printing has been used as an additive manufacturing technology for fabricating flexible antenna in recent years.

Effect of interstitial fluid pH on transdermal glucose extraction by reverse iontophoresis.

Reverse iontophoresis (RI) is a promising technology in the field of continuous glucose monitoring (CGM), offering significant advantages such as finger-stick-free operation, wearability, and non-invasiveness. In the glucose extraction process based on RI, the pH of the interstitial fluid (ISF) is a critical factor that needs further investigation, as it directly influences the accuracy of transdermal glucose monitoring. In this study, a theoretical analysis was conducted to investigate the mechanism by which pH affects the glucose extraction flux.

Effect of Wettability on the Collision Behavior of Acoustically Excited Droplets.

Acoustic droplet ejection (ADE) is a noncontact technique for micro-liquid handling (usually nanoliters or picoliters) that is not restricted by nozzles and enables high-throughput liquid dispensing without sacrificing precision. It is widely regarded as the most advanced solution for liquid handling in large-scale drug screening. Stable coalescence of the acoustically excited droplets on the target substrate is a fundamental requirement during the application of the ADE system.

Electrically Inspired Flexible Electrochemical Film Power Supply for Long-Term Epidermal Sensors.

This paper, for the first time, reports an electrically inspired flexible electrochemical film power supply for long-term epidermal sensors. This device can periodically provide electrical power for several hours after a short-time electrical activation. The electrical activation makes acetylcholine, which is infused into the subcutaneous tissue by iontophoresis.

Flexible organic field-effect transistors-based biosensors: progress and perspectives.

Organic field-effect transistors (OFETs) have been proposed beyond three decades while becoming a research hotspot again in recent years because of the fast development of flexible electronics. Many novel flexible OFETs-based devices have been reported in these years. Among these devices, flexible OFETs-based sensors made great strides because of the extraordinary sensing capability of FET.

Reverse iontophoresis with the development of flexible electronics: A review.

Skin-centric diagnosis techniques, such as epidermal physiological parameter monitoring, have developed rapidly in recent years. The analysis of interstitial fluid (ISF), a body liquid with abundant physiological information, is a promising method to obtain health status because ISF is easily assessed by implanted or percutaneous measurements. Reverse iontophoresis extracts ISF by applying an electric field onto the skin, and it is a promising method to noninvasively obtain ISF, which, in turn, enables noninvasive epidermal physiological parameter monitoring.

Cell mechanical responses to subcellular perturbations generated by ultrasound and targeted microbubbles.

The inherently dynamic and anisotropic microenvironment of cells imposes not only global and slow physical stimulations on cells but also acute and local perturbations. However, cell mechanical responses to transient subcellular physical signals remain unclear. In this study, acoustically activated targeted microbubbles were used to exert mechanical perturbations to single cells.

Mechanobiology Platform Realized Using Photomechanical Mxene Nanocomposites: Bilayer Photoactuator Design and In Vitro Mechanical Forces Stimulation.

Mechanotransduction is the process by which cells convert external forces and physical constraints into biochemical signals that control several aspects of cellular behavior. A number of approaches have been proposed to investigate the mechanisms of mechanotransduction; however, it remains a great challenge to develop a platform for dynamic multivariate mechanical stimulation of single cells and small colonies of cells. In this study, we combined polydimethylsiloxane (PDMS) and PDMS/Mxene nanoplatelets (MNPs) to construct a soft bilayer nanocomposite for extracellular mechanical stimulation.

Modular Microfluidics: Current Status and Future Prospects.

This review mainly studies the development status, limitations, and future directions of modular microfluidic systems. Microfluidic technology is an important tool platform for scientific research and plays an important role in various fields. With the continuous development of microfluidic applications, conventional monolithic microfluidic chips show more and more limitations.

A Fiber-Based SPR Aptasensor for the In Vitro Detection of Inflammation Biomarkers.

It is widely accepted that the abnormal concentrations of different inflammation biomarkers can be used for the early diagnosis of cardiovascular disease (CVD). Currently, many reported strategies, which require extra report tags or bulky detection equipment, are not portable enough for onsite inflammation biomarker detection. In this work, a fiber-based surface plasmon resonance (SPR) biosensor decorated with DNA aptamers, which were specific to two typical inflammation biomarkers, C-reactive protein (CRP) and cardiac troponin I (cTn-I), was developed.

Influence of Surface Tension on Dynamic Characteristics of Single Bubble in Free-Field Exposed to Ultrasound.

The motion of bubbles in an ultrasonic field is a fundamental physical mechanism in most applications of acoustic cavitation. In these applications, surface-active solutes, which could lower the surface tension of the liquid, are always utilized to improve efficiency by reducing the cavitation threshold. This paper examines the influence of liquids' surface tension on single micro-bubbles motion in an ultrasonic field.

DNA-Based Biosensors for the Biochemical Analysis: A Review.

In recent years, DNA-based biosensors have shown great potential as the candidate of the next generation biomedical detection device due to their robust chemical properties and customizable biosensing functions. Compared with the conventional biosensors, the DNA-based biosensors have advantages such as wider detection targets, more durable lifetime, and lower production cost. Additionally, the ingenious DNA structures can control the signal conduction near the biosensor surface, which could significantly improve the performance of biosensors.

Controllable Droplet Ejection of Multiple Reagents through Focused Acoustic Beams.

Acoustic droplet ejection (ADE) technology has revolutionized fluid handling with its contactless and fast fluid transfer. For precise droplet ejection and stable droplet coalescence at the target substrates for further detection, the input power of the ADE system needs to be adjusted. Currently, the existing power control method depends on scanning the source fluid wells one by one, which cannot afford precise and highly efficient droplet velocity adjustment, and the complicated operation caused by the repeated power evaluation processes for thousands of fluid transfers will waste much time.

Effects of surface tension on the dynamics of a single micro bubble near a rigid wall in an ultrasonic field.

Acoustic cavitation is a very important hydrodynamic phenomenon, and is often implicated in a myriad of industrial, medical, and daily living applications. In these applications, the effect mechanism of liquid surface tension on improving the efficiency of acoustic cavitation is a crucial concern for researchers. In this study, the effects of liquid surface tension on the dynamics of an ultrasonic driven bubble near a rigid wall, which could be the main mechanism of efficiency improvement in the applications of acoustic cavitation, were investigated at the microscale level.

A review on acoustic droplet ejection technology and system.

The pace of change in chemical and biological research enabled by improved detection systems demands fundamental liquid handling and sample preparation changes. The acoustic droplet ejection (ADE)-based liquid handling method has the advantages of improving precision and data reproducibility, reducing costs, hands-on time, and eliminating waste. ADE gradually replaced traditional aspiration-and-dispense liquid-handling robots in applications such as synthetic biology, genotyping, personalized medicine, and next-generation sequencing.

A thermal activated and differential self-calibrated flexible epidermal biomicrofluidic device for wearable accurate blood glucose monitoring.

This paper reports a flexible electronics-based epidermal biomicrofluidics technique for clinical continuous blood glucose monitoring, overcoming the drawback of the present wearables, unreliable measurements. A thermal activation method is proposed to improve the efficiency of transdermal interstitial fluid (ISF) extraction, enabling extraction with a low current density to notably reduce skin irritation. An Na sensor and a correction model are proposed to eliminate the effect of individual differences, which leads to fluctuations in the amount of ISF extraction.

Energy and Charge Transport in 2D Atomic Layer Materials: Raman-Based Characterization.

As they hold extraordinary mechanical and physical properties, two-dimensional (2D) atomic layer materials, including graphene, transition metal dichalcogenides, and MXenes, have attracted a great deal of attention. The characterization of energy and charge transport in these materials is particularly crucial for their applications. As noncontact methods, Raman-based techniques are widely used in exploring the energy and charge transport in 2D materials.