Electro-pneumatic pumps for soft robotics

Soft robotics has applications in myriad fields from assistive wearables to autonomous exploration. Now, the portability and the performance of many devices are limited by their associated pneumatic energy source, requiring either large, heavy pressure vessels or noisy, inefficient air pumps. Here, we present a lightweight, flexible, electro-pneumatic pump (EPP), which can silently control volume and pressure, enabling portable, local energy provision for soft robots, overcoming the limitations of existing pneumatic power sources. The EPP is actuated using dielectric fluid–amplified electrostatic zipping, and the device presented here can exert pressures up to 2.34 kilopascals and deliver volumetric flow rates up to 161 milliliters per second and under 0.5 watts of power, despite only having a thickness of 1.1 millimeters and weight of 5.3 grams. An EPP was able to drive a typical soft robotic actuator to achieve a maximum contraction change of 32.40% and actuation velocity of 54.43% per second. We highlight the versatility of this technology by presenting three EPP-driven embodiments: an antagonistic mechanism, an arm-flexing wearable robotic device, and a continuous-pumping system. This work shows the wide applicability of the EPP to enable advanced wearable assistive devices and lightweight, mobile, multifunctional robots.

Soft pumps for soft robots

A light and portable soft electro-pneumatic pump could power future soft robots.

An absorption spectrophotometer compatible paper-based thin-layer cuvette with an integrated pneumatic pump

This study presents a paper-based thin-layer optical cuvette for absorption spectroscopy with a pneumatically driven pump for the introduction of an aqueous sample. The three major components, including a sample...

ВИЗНАЧЕННЯ КОЕФІЦІЄНТУ КОРИСНОЇ ДІЇ ДВОКОМПОНЕНТНОГО ПНЕВМОНАСОСНОГО АГРЕГАТУ ДЛЯ КОСМІЧНОГО АПАРАТА

Research has been carried out to determine the efficiency of the piston pneumatic pump unit (PPU) of two-way action for the fuel supply system of a spacecraft operating on propellants of AT and MMH (UDMH). The PPU relates to volumetric pumps, therefore, the efficiency is defined as the ratio of effective work performed by the PPU to the expended gas work. The range of total propellants flow rates from 100 to 240 g/s through the PPU is determined by the operating modes of main engine and steering thrusters. As a result of performed researches, the PPU efficiency and main factors influencing on its value were theoretically determined, namely: gas losses for filling "parasitic" volumes including the volumes that do not participate in the process of fluid displacement from hydraulic pumps (volumes associated with incomplete fit of the pneumatic pistons to the bottoms of the pneumatic cylinders, the volume of control and supply channels), but are ejected into the environment at each operation of the PPU pneumatic distributor together with the volume of gas that performed effective work; gas ejections through the drainage seats into the environment at pneumatic distributors switchings, since at pneumatic distributors switchings some cavities are connected with the power supply source by control pressure, and other ones - with environment by poppet moving from the feed seat to the drainage seat; inlet air (helium) pressure losses due to the resistance of gas channels of the pneumatic distributors; friction of seals with fluoroplastic collars of the piston blocks; resistance of the hydraulic channels which components are: pressure losses of non-return valves and hydraulic channels; displaced fluid volume decreasing by hydraulic pumps due to leakage of non-return valves, piston collars and hydraulic pumps rods. The bipropellant PPU efficiency was theoretically and experimentally determined at different operating modes. The calculated value of the efficiency is well confirmed by experiments at that the divergence does not exceed 4%. The results of this research will allow us to determine the necessary gas reserves on board of spacecraft at the stage of designing.

Dexterous Hybrid Robotics for High Precision Applications

Robotic grippers are useful in designing prosthetics and manufacturing. “Robotic hands often fall into two categories: simple and highly specialized grippers often used in manufacturing, and general and highly complicated grippers designed for a variety of tasks.” Ramond et al. [1] Within these two categories there are two main categories of research. These are hard structure and soft structure robotics. Hard structure robotics rely on a mechanical design with a motor or actuator to move a hard-linked part. Soft structure uses a mechanical design, soft material and a pneumatic pump to create the desired movement. The soft material is designed in a way that when it is pumped full of a fluid (i.e. air) it has a specific deformation. Hard robotics have an advantage in their ability to output a large force, but soft robotics have increased degrees of freedom. Dexterity (readiness and grace in physical movement) is another advantage over hard robotics. This project focuses on the process of designing actuators that can feasibly be used for devices falling into either of the two main categories of robotics. Such an actuator could be effectively implemented toward simple applications such as manufacturing-style gripping devices to advanced applications found in modern human prosthetics or areas where high dexterity combined with a delicate touch are required. The simulations show that the designs created work within a pressure range of 0.5 PSI to 1 PSI. This low pressure does not output a lot of force. The high dexterity and small air compressors needed make it a good design for use in areas like manufacturing or medical. If a stronger material was applied to these designs allowing the designs to handle higher pressures these designs could output much higher forces. This increase would make the designs more usable in areas like prosthetics and advanced robotics.

A novel concept of pneumatic pump in the outpatient management of mixed leg ulceration: a pilot study

Mixed leg ulcer is a challenge in vascular diseases because both arterial and venous systems of the lower extremities are involved in the wound pathogenesis. Management is very difficult because the coexistence of the two conditions sometimes prevent to use compression bandaging, which is the cornerstone of venous leg ulcer treatment. It has been recently developed the so called gradient pump (GP), a novel device which permits to intermittently stop the flow in the femoral vein with a pneumatic cuff placed on the thigh. Subsequent release of the femoral vein compression determines a dramatic aspiration of the blood up-ward the heart, with synchronous and measured improved perfusion of the distal limb. We applied GP at 4 consecutive cases of multiple mixed painful ulcerations of the foot and leg scheduled for below knee and/or foot amputations. In all cases measure of pain by visual analogue scale significantly decreased; GP in most cases together intravenous infusion of synthetic prostacyclin led to improvement and/or minimal amputation. Therefore such a management can be done on outpatient bases, allowing a considerable lowering of health costs. We conclude that GP could be a valuable tool in the arsenal of mixed leg ulcer clinical assessment.