Reshapeable,rehealable and recyclable sensor fabricated by direct ink writing of conductive composites based on covalent adaptable network polymers

Covalent adaptable network(CAN)polymers doped with conductive nanoparticles are an ideal candidate to create reshapeable,rehealable,and fully recyclable electronics.On the other hand,3D printing as a deterministic manufacturing method has a significant potential to fabricate electronics with low cost and high design freedom.In this paper,we incorporate a conductive composite consisting of polyimine CAN and multi-wall carbon nanotubes into direct-ink-writing 3D printing to create polymeric sensors with outstanding reshaping,repairing,and recycling capabilities.The developed printable ink exhibits good printability,conductivity,and recyclability.The conductivity of printed polyimine composites is investigated at different temperatures and deformation strain levels.Their shape-reforming and Joule heating-induced interfacial welding effects are demonstrated and characterized.Finally,a temperature sensor is 3D printed with defined patterns of conductive pathways,which can be easily mounted onto 3D surfaces,repaired after damage,and recycled using solvents.The sensing capability of printed sensors is maintained after the repairing and recycling.Overall,the 3D printed reshapeable,rehealable,and recyclable sensors possess complex geometry and extend service life,which assist in the development of polymer-based electronics toward broad and sustainable applications.

PD-1 abrogates the prolonged persistence of CD8+CAR-T cells with 4-1BB co-stimulation

Dear Editor,The central memory differentiation critically dictates CAR-T cell persistence,which is closely associated with the therapeutic effectiveness in the clinic.It is well accepted that 4-1BB costimulation is superior over CD28 to promote the central memory differentiation and persistence of CAR-T cells.1 However,it is also noticed that CAR-T cells with either co-stimulations are comparably differentiated and persisted,2 especially under immunosuppressive conditions.Factors contributing to the discrepancy remain unknown.Mounting evidences show that programmed cell death protein 1(PD-1)directly affects memory differentiation of T cells upon PD-L1 engagement,3 in addition to limiting proliferation.It is unclear whether PD-1 is involved in the diminished difference in memory differentiation and persistence between CAR-T cells with different co-stimulations.Herein,we examined the memory differentiation of CAR-T cells when PD-1 is activated or not,and consequently the persistence and anti-tumor effects.

Hydrogel-elastomer-based stretchable strain sensor fabricated by a simple projection lithography method

Stretchable strain sensor detects a wide range of strain variation and is therefore a key component in various applications.Unlike traditional ones made of elastomers doped with conductive components or fabricated with liquid conductors,ionically conductive hydrogel-based strain sensors remain conductive under large deformations and are biocompatible.However,dehydration is a challenging issue for the latter.Researchers have developed hydrogel-elastomer-based strain sensors where an elastomer matrix encapsulates a hydrogel circuit to prevent its dehydration.However,the reported multistep approaches are generally time-consuming.Our group recently reported a multimaterial 3D printing approach that enables fast fabrication of such sensors,yet requires a self-built digital-light-processing-based multimaterial 3D printer.Here,we report a simple projection lithography method to fabricate hydrogel-elastomer-based stretchable strain sensors within 5 minutes.This method only requires a UV projector/lamp with photomasks;the chemicals are commercially available;the protocols for preparing the polymer precursors are friendly to users without chemistry background.Moreover,the manufacturing flexibility allows users to readily pattern the sensor circuit and attach the sensor to a 3D printed soft pneumatic actuator to enable strain sensing on the latter.The proposed approach paves a simple and versatile way to fabricate hydrogel-elastomer-based stretchable strain sensors and flexible electronic devices.

A Research on Ideological and Political Education Development of Noble Family Moral

As a cultural and social phenomenon, noble family moral is characterized with history, complexity, nationality, and time. It also has hierarchical contents related to individual, social and national levels. As an origin of cultural environment for most people’s growth, noble family moral plays an important role in ideological and political education by setting up appropriate environment, facilities, and manner. At the important development stage of the socialist modernization in our country, noble family moral should be put in practice and developed to strengthen ideological and political education. Various methods, such as intergenerational inheritance, community infl uence, development and innovation of family moral would contribute to the build-up of socialist harmonious society.