Elastic Inflatable Actuators for Soft Robotic Applications

The 20th century’s robotic systems have been made out of stiff materials and much of the developments in the field have pursued ever more accurate and dynamic robots which thrive in industrial automation settings and will probably continue to do so for many decades to come. However, the 21st century’s robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfil the role of robotic link and robotic actuator, where prime focus is on design and fabrication of the robotic hardware instead of software control to achieve a desired operation. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators to generate movement. This paper reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained substantial traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies including soft-lithography and additive manufacturing, and on the other hand by a market pull from the applications listed above. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication and applications.This research is supported by the Fund for Scientific Research-Flanders (FWO), and the European Research Council (ERC starting grant HIENA)

Elastic Inflatable Actuators for Soft Robotic Applications

The 20th century’s robotic systems have been made out of stiff materials and much of the developments in the field have pursued ever more accurate and dynamic robots which thrive in industrial automation settings and will probably continue to do so for many decades to come. However, the 21st century’s robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfil the role of robotic link and robotic actuator, where prime focus is on design and fabrication of the robotic hardware instead of software control to achieve a desired operation. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators to generate movement. This paper reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained substantial traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies including soft-lithography and additive manufacturing, and on the other hand by a market pull from the applications listed above. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication and applications.This research is supported by the Fund for Scientific Research-Flanders (FWO), and the European Research Council (ERC starting grant HIENA)

NASA SBIR abstracts of 1991 phase 1 projects

The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

A Novel Propeller Design for Micro-Swimming robot

The applications of a micro-swimming robot such as minimally invasive surgery, liquid pipeline robot etc. are widespread in recent years. The potential application fields are so inspiring, and it is becoming more and more achievable with the development of microbiology and Micro-Electro-Mechanical Systems (MEMS). The aim of this study is to improve the performance of micro-swimming robot through redesign the structure. To achieve the aim, this study reviewed all of the modelling methods of low Reynolds number flow including Resistive-force Theory (RFT), Slender Body Theory (SBT), and Immersed Boundary Method (IBM) etc. The swimming model with these methods has been analysed. Various aspects e.g. hydrodynamic interaction, design, development, optimisation and numerical methods from the previous researches have been studied. Based on the previous design of helix propeller for micro-swimmer, this study has proposed a novel propeller design for a micro-swimming robot which can improve the velocity with simplified propulsion structure. This design has adapted the coaxial symmetric double helix to improve the performance of propulsion and to increase stability. The central lines of two helical tails overlap completely to form a double helix structure, and its tail radial force is balanced with the same direction and can produce a stable axial motion. The verification of this design is conducted using two case studies. The first one is a pipe inspection robot which is in mm scale and swims in high viscosity flow that satisfies the low Reynolds number flow condition. Both simulation and experiment analysis are conducted for this case study. A cross-development method is adopted for the simulation analysis and prototype development. The experiment conditions are set up based on the simulation conditions. The conclusion from the analysis of simulation results gives suggestions to improve design and fabrication for the prototype. Some five revisions of simulation and four revisions of the prototype have been completed. The second case study is the human blood vessel robot. For the limitations of fabrication technology, only simulation is conducted, and the result is compared with previous researches. The results show that the proposed propeller design can improve velocity performance significantly. The main outcomes of this study are the design of a micro-swimming robot with higher velocity performance and the validation from both simulation and experiment

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Exploration of an electro-magneto-responsive polymeric drug delivery system for enhanced nose-to-brain delivery

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand in fulfilment of the requirements for the degree of Doctor of PhilosophyDelivering drugs to the brain for the treatment of brain diseases has been fraught with low bioavailability of drugs due to the Blood-Brain Barrier (BBB). The intranasal (IN) route of delivery has purportedly been given recognition as an alternative route of delivering drugs to the brain with improved bioavailability if the nose-to-brain option is considered. However, drugs administered through the nasal mucosa suffer some challenges such as mucocilliary clearance, enzymatic degradation, inability of a controllable drug release to give a precise dose, resulting in frequent dosing and absorption into the systemic circulation through the blood rich vessels in the mucosa, thus facing the BBB challenge. The aim of this study was to develop a novel Nano-co-Plex (NCP), a magnetic nano-carrier loaded with a therapeutic agent which is further incorporated into a nasal thermosensitive electro-responsive mucogel (TERM) for in situ gelling, for electroactuated release of the incorporated drug-loaded NCP in a controllable “on-off” pulsatile manner, which is achieved with the aid of an external electric stimulation (ES). The released drug-loaded NCP was then targeted to the brain via a direct nose-to-brain drug delivery pathway with the aid of an external magnetic field (MF) for rapid transportation. The ES was brought about by applying a 5V potential difference (PD) using electrodes on the nose and the external MF would then be applied by placing a magnetic headband on the head of the patient. In this research, the drug-loaded NCP was prepared by firstly synthesizing iron oxide nanoparticles (Magnetite) which were then coated with Polyplex; a polymeric complex fabricated employing polyvinyl alcohol (PVA), polyethyleneimine (PEI) and fIuorecein isothiocyanate (FITC). The coated magnetite was thereafter loaded with Carmustine (BCNU), an effective drug commonly used in brain tumor treatment, to formulate the BCNU-NCP. The TERM was prepared by blending a thermosensitive polymer, Pluronic F127 (F127) with mucoadhesive polymers, chitosan (CS) and hydroxypropyl methylcellulose (HPMC). Polyaniline (PANI) was included in the blend as the electo-active moiety of the formulation. Finally, the BCNU-NCP was incorporated into the gel to form a Nanogel- Composite. A Box–Behnken design model was employed for the optimization of the Nanogel Composite. TERM, BCNU-NCP and Nanogel Composite were characterized employing Thermogravimetric analysis (TGA), Superconducting Quantum Interference Device (SQUID) magnetometry, Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM), Cyclic Voltammetry (CV), Transmission Electron Microscopy (TEM), Rheological, Porositometry, Textural and Zetasize analyses. In vitro drug release, ex vivo permeation and in vivo studies were performed. The BCNU-NCP was found to be paramagnetic with a magnetization value of 61emu/g, possessing a mixture of spherical and hexagonal shaped core-shell nanoparticles of size 30-50nm with zeta potential of +32 ±2mV. The NCP displayed a high degree of crystallinity with 32% Polyplex coating. The loading capacity of NCP was 176.86μg BCNU/mg of the carrier and maximum release of 75.8% of the loaded BCNU was achieved after 24 hours. FTIR and NMR confirmed the conjugation of PVA and PEI of the Polyplex at a ratio of 1:4. Cytotoxicity of the BCNU-loaded Nano-co-Plex displayed superiority over the conventional BCNU towards human glioblastoma (HG) A170 cells. Cell studies revealed enhanced uptake and internalization of BCNU-NCP in HG A170 cells in the presence of an external MF. BCNU-NCP was found to be non-toxic to healthy brain cells. A thermally stable gel with desirable rheological and mucoadhesive properties was developed. The results revealed gelation temperature of 27.5±0.5°C with a porous morphology. Nanogel Composite possesses electroactive properties and shows response to ES and releases incorporated BCNU-NCP in an “on-off” pulsatile drug release profile upon application of a 5V PD. The in vitro release studies showed an average release of BCNU-NCP per release cycle to be 10.28%. Ex vivo permeation studies were performed using a freshly excised nasal tissue of the New Zealand white rabbit; the results showed that BCNU-NCP was able to permeate through the nasal tissue at a 6 times greater amount in the presence of a MF than in the absence of MF. BCNU concentration was found to be high in the brain and CSF of rabbit when the Nanogel Composite is intranasally administered compared to the IV injection of the conventional BCNU. Furthermore, application of the MF was found to increase the concentration of BCNU in the brain and CSF of the rabbit. The result of Field Emission Electron Probe Micro Analyzer (FE EPMA) was further used to confirm the presence of NCP in the rabbit brain tissue. Histopathological results indicated mild lesions in the nasal mucosa of the rabbit after IN administration of Nanogel Composite. The results of the in vitro, ex vivo and the in vivo proved that the Nanogel Composite is superior in delivering BCNU into the brain than the conventional drug delivery system for the treatment of brain tumor as it was able to release the therapeutic agent in a controllable manner. The MF applied aided drug to be targeted and rapidly transported to the brain via a direct nose-to-brain pathway thereby circumventing the BBB and increasing bioavailability of drug in the brain. This vehicle may also be used to deliver other similar therapeutic agents into the brain for the treatment of various brain diseases.MB201

Electrospinning piezoelectric fibers for biocompatible devices

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and nanogenerators for the human body. This paper provides a comprehensive review of current studies focused on the fabrication of ultrafine polymeric and ceramic piezoelectric fibers specifically designed for, or with the potential to be translated toward, biomedical applications. It provides an applicative and technical overview of the biocompatible piezoelectric fibers, with actual and potential applications, an understanding of the electrospinning process, and the properties of nanostructured fibrous materials, including the available modeling approaches. Ultimately, this review aims at enabling a future vision on the impact of these nanomaterials as stimuli-responsive devices in the human body

A STUDY ON DYNAMIC SYSTEMS RESPONSE OF THE PERFORMANCE CHARACTERISTICS OF SOME MAJOR BIOPHYSICAL SYSTEMS

Dynamic responses of biophysical systems - performance characteristic