New Energy Technologies

Nature is full of energy, but we haven’t found ways to harness all of the myriad forms yet. New renewable energy technologies can appear overnight when a person see’s a viable way to harness the abundant energy found throughout nature.

Artificial Muscle Electricity Generator

One example of this involves the new discovery of an old product – fishing string. Who doesn’t know fishing string? Now, scientists have discovered a remarkable property of fishing string…it can be used as a very low cost artificial muscle.

The amazing properties of fishing line as fibre for artificial muscle is shown here. By cycling hot and cold water over the muscle, it can generate power, up to 7 HP per kilogram. This doesn’t sound like much to the uninitiated but it is actually more power density than a jet engine. The authors describe the work in this Abstract:

Abstract:

The high cost of powerful, large-stroke, high-stress artificial muscles has combined with performance limitations such as low cycle life, hysteresis, and low efficiency to restrict applications. We demonstrated that inexpensive high-strength polymer fibers used for fishing line and sewing thread can be easily transformed by twist insertion to provide fast, scalable, nonhysteretic, long-life tensile and torsional muscles. Extreme twisting produces coiled muscles that can contract by 49%, lift loads over 100 times heavier than can human muscle of the same length and weight, and generate 5.3 kilowatts of mechanical work per kilogram of muscle weight, similar to that produced by a jet engine. Woven textiles that change porosity in response to temperature and actuating window shutters that could help conserve energy were also demonstrated. Large-stroke tensile actuation was theoretically and experimentally shown to result from torsional actuation.

Description of artificial muscle made with fishing string (Source: Haines et al.)

 

Description of a New Energy Generation Invention based upon Artificial Muscles made of Inexpensive High-Strength Polymer Fibers

On Mar 1, 2016, herein now is disclosed an invention built upon such a principle that is made freely available to the commons. Being revealed in the public domain, it is not patentable and belongs to the commons and furthermore is protected by a share and share alike Creative Commons license. This disclosure was edited on Mar 2, 2016 to expand the original design claim so that direct heating or cooling of the fibre or other means or alternately heating and cooling the fibre can be applied, and not just through fluid.

Abstract

The invention is a temperature differential power generator that leverages the macroscopic thermal expansion characteristics of inexpensive high-strength polymer fibers. The fibre filaments are mechanically wound and annealed around a mandrel at elevated temperatures, form strong linear fibre bundles with the right characteristics of thermal expansion and contraction. The fibre bundle is affixed to a frame on one side and connected to a mass body on the other side. The device possesses a multiplicity of means to induce regular, alternating heat flow into and out of the fibre bundle to induce thermal contraction /expansion. Due to the large thermal expansion effect and the strength of the fibre bundle, this moves the mass body to perform mechanical work. Direct heating (ie. from Concentrated Solar Power devices) or indirect heating (ie. fluid heat transfer) can be applied to fibre bundle to bring about the temperature cycling and resultant contraction/expansion cycle.  The resultant linear reciprocating motion of the fibre bundle and respective attached mass body can be harnessed to perform direct mechanical work. Alternatively, it can be converted into rotational motion for direct mechanical work or converted via a regular stator/rotor electrical winding pair to generate alternating current electricity. The mechanical translation from linear reciprocating motion to rotational can be done with any number of mechanical devices such as cams, slider-crank, scotch-and-yoke, etc…The power of the fibre bundle can be multiplied by ganging together more than one of them.

The inexpensive high-strength polymer fibers normally used in the invention is monofilament fishing line, coiled in the way described by the source work Artificial Muscles from Fishing Line and Sewing Thread by Haines et al. Described below are technological variants of the claimed invention.

Direct Heating Method

Concentrated Solar Power (CSP) is an established field of technology. Principles of solar insolation, fresnel lens, concentrating parabolic mirrors, parabolic mirror troughs, concentrating solar towers and the like can be applied to directly heat the fibre bundles. The energy at the focal point must be controlled to be of a more diffuse nature due to the low melting point of the fishing line material properties.

When concentrated solar techniques are used, the maximum safe temperature causes the fibre filament to expand. The fibre bundle and attached metal weight is vertically suspended above the surface of a large body of cool water, and the CSP concentrator focal point is designed to be placed along the axis of the fibre bundle. Alternatively, direct solar insolation can be used by temporarily enclosing the fibre bundle in a black container that efficiently absorbs solar insolation. If Fresnel lens is used, a sun tracking system may be necessary. If a CSP device such as Fresnel lens or specular mirror reflector is used to focus sunlight onto the linear focal beam along the axis of the fibre bundle, the CSP device is fitted with a shutter which can be alternately opened or closed, depending on the switch position triggered by the fibre bundles movement along its axis of motion.

In the expansion cycle, the CSP shutter is open, allowing photonic energy to impinge upon the surface of the fibre bundle, causing thermal expansion and the fibre bundle, along with attached mass to move vertically downwards. At a certain point in time, the weight descends through the surface of the large cool body of water. The cooling water, acting through the metal suspended mass causes the fibre bundle to cool via thermal conductivity effect. During this part of the cycle, it also causes a switch to be triggered which closes the CSP shutter or generally removes/switches off the heat source applied to the fibre. The thermal conductivity of the cool water in contact with the metal weight and removal of the heat source accelerate the cooling cycle, causing the fibre bundle and weight to begin travelling upwards.

It may also be possible to arrange the motion to be horizontal rather than vertical.

Indirect Heating Method

Indirect heating method relies on fluids or tubes that carry heat transfer fluids and relies on thermal conductivity exclusively.

A fluid to immerse the bundles sufficiently to maximize expansion/contraction. Each fibre bundle is attached to a fixed frame on one side and the other end of the fibre bundle connects another object putting it in tension. A typical application is to orient the fibre bundle in a vertical position from which is suspended a heavy weight which sits above the surface of a large water mass such as a river, lake, ocean or even man-made bodies of water or water tanks in industry.  The fibre bundle may further be encased in a watertight chamber which can be alternative flooded with hot or cold water. When cold and hot fluid is alternately cycled over the fibre bundle, it causes it to expand or contract, moving against the force and producing work.  Fibre bundles are constrained to move along its axis. Hot and cold fluid is cycled on regular intervals over the series of fibre bundles producing a regular sequence of fibre bundle reciprocating linear motion along each fibre bundle axis.

The warm water source is from solar thermal heating on a solar absorbent tank located near the fibre bundles. This tank supplies hot water to surround the fibre bundle and cause the thermal expansion cycle.  Colder water drawn from the large body of water immerses the fibre bundles in cold water, causing the contraction cycle. If the fibre bundles are oriented perpendicular to the surface of a large cold body of water, the design of the heating cycle could push the fibre into the cold water body itself, naturally cooling the fibre and beginning a contraction cycle. At this time, if a surrounding water chamber is used, it can be opened to release the warm water into the larger body of cold water. Syncrhonizing many reciprocating motion of many fibre bundles together can create a resultant power translated into alternating current.

Creative Commons License
Fishing Line Artificial Muscle, Fluid Differential Temperature Reciprocating Electrical Generator by James (Gien) Wong is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://science.sciencemag.org/content/343/6173/868.