scholarly journals Tethered and Untethered 3D Microactuators Fabricated by Two-Photon Polymerization: A Review

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 465
Author(s):  
Zhaoxin Lao ◽  
Neng Xia ◽  
Shijie Wang ◽  
Tiantian Xu ◽  
Xinyu Wu ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Microelectromechanical Systems ◽  
Smart Devices ◽  
Mems Devices ◽  
Stimuli Responsive ◽  
Laser Printing ◽  
Noninvasive Surgery ◽  
Two Photon ◽  
Processing Techniques ◽  
External Stimuli

Microactuators, which can transform external stimuli into mechanical motion at microscale, have attracted extensive attention because they can be used to construct microelectromechanical systems (MEMS) and/or microrobots, resulting in extensive applications in a large number of fields such as noninvasive surgery, targeted delivery, and biomedical machines. In contrast to classical 2D MEMS devices, 3D microactuators provide a new platform for the research of stimuli-responsive functional devices. However, traditional planar processing techniques based on photolithography are inadequate in the construction of 3D microstructures. To solve this issue, researchers have proposed many strategies, among which 3D laser printing is becoming a prospective technique to create smart devices at the microscale because of its versatility, adjustability, and flexibility. Here, we review the recent progress in stimulus-responsive 3D microactuators fabricated with 3D laser printing depending on different stimuli. Then, an outlook of the design, fabrication, control, and applications of 3D laser-printed microactuators is propounded with the goal of providing a reference for related research.

Microsensors, MEMS and NEMS Based Complex Adaptive Smart Devices and Systems

2001 ◽  
Author(s):  
Vijay K. Varadan
Keyword(s):  
Self Assembly ◽  
Communication Systems ◽  
Microelectromechanical Systems ◽  
System Level ◽  
Smart Devices ◽  
Mems Devices ◽  
Wafer Level ◽  
Sensors And Actuators ◽  
Complex Adaptive ◽  
Microelectronics Industry

Abstract The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and MicroElectroMechanical Systems (MEMS). This effort offers the promise of: 1. Increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed for the IC and microelectronics industry. Examples include micro stereo lithographic and micro molding techniques. 2. Developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines. 3. Development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation. 4. Development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems.

scholarly journals Potential of Stimuli-Responsive Star Polymer for Cancer Targeting

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Patihul Husni ◽  
Muhammad Alvien Ghifari ◽  
Norisca Aliza Putriana
Keyword(s):  
Targeted Delivery ◽  
Star Polymers ◽  
Star Polymer ◽  
Natural Phenomenon ◽  
Therapeutic Drug ◽  
Cancer Targeting ◽  
Linear Polymers ◽  
Stimuli Responsive ◽  
Redox Enzyme ◽  
External Stimuli

Application of stimuli-responsive star polymers in cancer targeting and drug delivery has been extensively researched because of their several advantages in comparison with their linear counterparts. Functionalization and recombination of various arm architectures of the star polymer are very possible to be conducted to suit various needs. The star polymers could not only load more therapeutic drug due to more arms than linear polymers but also be functionalized with targeted moieties for more targeted delivery. Furthermore, the chains in star polymers could be regulated to produce stimuli-responsive star polymer for cancer targeting. The review article aimed to describe the benefits of star polymers and the types of stimuli-responsive delivery system for cancer targeting. Over the last decade, stimuli-responsive star polymers for cancer targeting using either internal stimuli (e.g., pH, redox, enzyme, hypoxia) or external stimuli (e.g., thermal, ultrasound, light, magnetic) has garnered immense interest for researchers. Possibility to mimic a complex natural phenomenon  could be achieved by incorporating various stimuli-responsive functionalities in the star polymer.

scholarly journals Stimuli-responsive surfaces for switchable wettability and adhesion

2021 ◽  
Vol 18 (179) ◽  
pp. 20210162
Author(s):  
Chang Li ◽  
Ming Li ◽  
Zhongshi Ni ◽  
Qingwen Guan ◽  
Bamber R. K. Blackman ◽  
...  
Keyword(s):  
Contact Angles ◽  
Smart Devices ◽  
Stimuli Responsive ◽  
Liquid Transport ◽  
Adhesion Properties ◽  
Smart Surfaces ◽  
Biological Surfaces ◽  
Responsive Surfaces ◽  
Rose Petal ◽  
External Stimuli

Diverse unique surfaces exist in nature, e.g. lotus leaf, rose petal and rice leaf. They show similar contact angles but different adhesion properties. According to the different wettability and adhesion characteristics, this review reclassifies different contact states of droplets on surfaces. Inspired by the biological surfaces, smart artificial surfaces have been developed which respond to external stimuli and consequently switch between different states. Responsive surfaces driven by various stimuli, e.g. stretching, magnetic, photo, electric, temperature, humidity and pH, are discussed. Studies reporting on either atmospheric or underwater environments are discussed. The application of tailoring surface wettability and adhesion includes microfluidics/droplet manipulation, liquid transport and harvesting, water energy harvesting and flexible smart devices. Particular attention is placed on the horizontal comparison of smart surfaces with the same stimuli. Finally, the current challenges and future prospects in this field are also identified.

Smart Polymers and their Applications: A Review

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Gore S. A. ◽  
Gholve S. B. ◽  
Savalsure S. M. ◽  
Ghodake K. B. ◽  
Bhusnure O. G. ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Soluble ◽  
Solution Temperature ◽  
Smart Polymers ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Water Soluble Polymers ◽  
Commercial Applications ◽  
Stimuli Sensitive ◽  
External Stimuli

Smart polymers are materials that respond to small external stimuli. These are also referred as stimuli responsive materials or intelligent materials. Smart polymers that can exhibit stimuli-sensitive properties are becoming important in many commercial applications. These polymers can change shape, strength and pore size based on external factors such as temperature, pH and stress. The stimuli include salt, UV irradiation, temperature, pH, magnetic or electric field, ionic factors etc. Smart polymers are very promising applicants in drug delivery, tissue engineering, cell culture, gene carriers, textile engineering, oil recovery, radioactive wastage and protein purification. The study is focused on the entire features of smart polymers and their most recent and relevant applications. Water soluble polymers with tunable lower critical solution temperature (LCST) are of increasing interest for biological applications such as cell patterning, smart drug release, DNA sequencing etc.

The Smart Dual-Stimuli Responsive Nanoparticles for Controlled AntiTumor Drug Release and Cancer Therapy

2020 ◽  
Vol 20 ◽  
Author(s):  
Feng Wu ◽  
Fei Qiu ◽  
Siew Anthony Wai-Keong ◽  
Yong Diao
Keyword(s):  
Drug Delivery ◽  
Cancer Therapy ◽  
Drug Release ◽  
Targeted Delivery ◽  
Relevant Information ◽  
Therapeutic Effects ◽  
Stimuli Responsive ◽  
Control Effect ◽  
Chemotherapy Drugs ◽  
Excellent Control

Background: In recent years, the emergence of stimuli-responsive nanoparticles makes drug delivery more efficient. As an intelligent and effective targeted delivery platform, it can reduce the side effects generated during drug transportation while enhancing the treatment efficacy. The stimuli-responsive nanoparticles can respond to different stimuli at corresponding times and locations to deliver and release their drugs and associated therapeutic effects. Objective: This review aims to inform researchers on the latest advances in the application of dual-stimuli responsive nanoparticles in precise drug delivery, with special attention to their design, drug release properties, and therapeutic effects. Syntheses of nanoparticles with simultaneous or sequential responses to two or more stimuli (pH-redox, pH-light, redoxlight, temperature-magnetic, pH-redox-temperature, redox-enzyme-light, etc.) and the applications of such responsivity properties for drugs control and release have become a hot topic of recent research. Methods: A database of relevant information for the production of this review was sourced, screened and analyzed from Pubmed, Web of Science, SciFinder by searching for the following keywords: “dual-stimuli responsive”, “controlled release”, “cancer therapy”, “synergistic treatment”. Results: Notably, the nanoparticles with dual-stimuli responsive function have an excellent control effect on drug delivery and release, playing a crucial part in the treatment of tumors. They can improve the encapsulation and delivery efficiency of hydrophobic chemotherapy drugs, combine chemo-photothermal therapies, apply imaging function in the diagnosis of tumors and even conduct multi-drugs delivery to overcome multi-drugs resistance (MDR). Conclusion: With the development of smart dual-stimuli responsive nanoparticles, cancer treatment methods will become more diverse and effective. All the stimuli-responsive nanoparticles functionalities exhibited their characteristics individually within the single nanosystem.

scholarly journals Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO2 Thin Film

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 114
Author(s):  
Chang Lu ◽  
Qingjian Lu ◽  
Min Gao ◽  
Yuan Lin
Keyword(s):  
Optical Methods ◽  
Stimuli Responsive ◽  
Device Structure ◽  
Current State ◽  
Insulator Metal Transition ◽  
Potential Applications ◽  
Fs Laser ◽  
External Stimuli ◽  
Thz Applications ◽  
Thz Waves

The reversible and multi-stimuli responsive insulator-metal transition of VO2, which enables dynamic modulation over the terahertz (THz) regime, has attracted plenty of attention for its potential applications in versatile active THz devices. Moreover, the investigation into the growth mechanism of VO2 films has led to improved film processing, more capable modulation and enhanced device compatibility into diverse THz applications. THz devices with VO2 as the key components exhibit remarkable response to external stimuli, which is not only applicable in THz modulators but also in rewritable optical memories by virtue of the intrinsic hysteresis behaviour of VO2. Depending on the predesigned device structure, the insulator-metal transition (IMT) of VO2 component can be controlled through thermal, electrical or optical methods. Recent research has paid special attention to the ultrafast modulation phenomenon observed in the photoinduced IMT, enabled by an intense femtosecond laser (fs laser) which supports “quasi-simultaneous” IMT within 1 ps. This progress report reviews the current state of the field, focusing on the material nature that gives rise to the modulation-allowed IMT for THz applications. An overview is presented of numerous IMT stimuli approaches with special emphasis on the underlying physical mechanisms. Subsequently, active manipulation of THz waves through pure VO2 film and VO2 hybrid metamaterials is surveyed, highlighting that VO2 can provide active modulation for a wide variety of applications. Finally, the common characteristics and future development directions of VO2-based tuneable THz devices are discussed.

scholarly journals Metal-Organic Framework-Based Stimuli-Responsive Polymers

2021 ◽  
Vol 5 (4) ◽  
pp. 101
Author(s):  
Menglian Wei ◽  
Yu Wan ◽  
Xueji Zhang
Keyword(s):  
Metal Organic Framework ◽  
Chemical Properties ◽  
Stimuli Responsive ◽  
Guest Molecules ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Reversible Phase Transition ◽  
Metal Organic ◽  
External Stimuli ◽  
Organic Framework

Metal-organic framework (MOF) based stimuli-responsive polymers (coordination polymers) exhibit reversible phase-transition behavior and demonstrate attractive properties that are capable of altering physical and/or chemical properties upon exposure to external stimuli, including pH, temperature, ions, etc., in a dynamic fashion. Thus, their conformational change can be imitated by the adsorption/desorption of target analytes (guest molecules), temperature or pressure changes, and electromagnetic field manipulation. MOF-based stimuli responsive polymers have received great attention due to their advanced optical properties and variety of applications. Herein, we summarized some recent progress on MOF-based stimuli-responsive polymers (SRPs) classified by physical and chemical responsiveness, including temperature, pressure, electricity, pH, metal ions, gases, alcohol and multi-targets.

Self-assembled peptide and protein nanostructures for anti-cancer therapy: Targeted delivery, stimuli-responsive devices and immunotherapy

Nano Today ◽  
2021 ◽  
Vol 38 ◽  
pp. 101119
Author(s):  
Masoud Delfi ◽  
Rossella Sartorius ◽  
Milad Ashrafizadeh ◽  
Esmaeel Sharifi ◽  
Yapei Zhang ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Targeted Delivery ◽  
Stimuli Responsive ◽  
Anti Cancer ◽  
Self Assembled

MICROFABRICATED ORAL DRUG DELIVERY SYSTEMS

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (11) ◽  
pp. 5-13
Author(s):  
A Shetty ◽  
◽  
G Srinivasan
Keyword(s):  
Drug Delivery ◽  
Integrated Circuit ◽  
Targeted Delivery ◽  
Microelectromechanical Systems ◽  
Film Growth ◽  
Oral Drug Delivery ◽  
Complete Solution ◽  
Oral Drug ◽  
Safe Delivery ◽  
Multiple Drugs

Microfabrication is a collection of techniques developed to fabricate micron sized features, best suited to develop the novel drug delivery microdevices. microfabrication techniques were originally developed in the microelectronics industry to produce functional devices on the micron scale such as sensors, switches, filters and gears. Approaches like modification of drug itself to improve its permeability/ solubility characters, encapsulation techniques using micro/nanoparticles, use of protease inhibitors to curb proteolytic degradation, and use of intelligent polymers and hydrogels do not offer a complete solution for adequate and safe delivery of drugs, vaccines, peptides, proteins and others. This technology has been applied to the successful fabrication of a variety of implantable and oral drug delivery devices based on silicon, glass, silicone elastomer or plastic materials. These techniques that are utilized at present have developed as a result of integrated circuit manufacturing technologies, such as photolithography, thin film growth/deposition, etching and bonding. Micromachining allows for control over surface features, aspect ratio, particle size, shape and facilitating the development of an engineered particle for drug delivery that can incorporate the advantages of microparticles while avoiding their design flaws. It helps in multi-cell and multi-site attachment, multiple reservoirs of desired size to contain multiple drugs/biomolecules of interest. These fabrication techniques have led to the development of microelectromechanical systems (MEMS), bioMEMS, micro-total analysis systems (μ-TAS), lab-on-a-chip and other microdevices. Microfabricated devices are designed for uni-directional release, to prevent enzyme degradation, precise dosing and better patient compliance. Drug delivery in the form of microparticles and micropatches have been used for targeted delivery as well as in treatment of diseases like diabetes and cancer.

External Stimuli-Responsive Nanoparticles for Spatially and Temporary Controlled Delivery of CRISPR-Cas Genome Editors

2021 ◽  
Author(s):  
Ruosen Xie ◽  
Yuyuan Wang ◽  
Shaoqin Gong
Keyword(s):  
Genome Editing ◽  
Genetic Diseases ◽  
Delivery Systems ◽  
Controlled Delivery ◽  
Stimuli Responsive ◽  
New Therapies ◽  
External Stimuli

The CRISPR–Cas9 system is a powerful tool for genome editing, which can potentially lead to new therapies for genetic diseases. Up to date, various viral and non-viral delivery systems have...

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