A magnetic nano (often shortened to just nano) is a small metal container, measuring a centimetre in height and width, with a screw-top lid and a thin, cylindrical magnet at its base. They often have an O-ring seal between the lid and the body to make them easier to open and partially waterproof.
Magnetic nanos were originally manufactured in 2001 to store flashing LED lights for use as jewellery, giving them the colloquial name 'blinkies'. [1] The LED went inside the lid, with two button batteries inside the nano's tube and a rare-earth magnet at the base, so the nano could attach to clothing and jewellery. [2]
When it was discovered that magnetic nanos can be used as geocache containers, they were quickly mass-produced and sold for that purpose. [2] They are widely known in the geocaching community as one of the smallest geocache containers. [3]
Magnetic nano geocaches only contain a thin, rolled-up paper sheet for geocachers to sign their username initials on. [4] [5]
Due to their very small size, they have become especially popular in urban locations (particularly cities), allowing for geocaches to easily be hidden in these areas. With larger geocaches, there are limitations to where urban geocaches can be well hidden without raising alarm. [6] Magnetic nanos, however, are often too small to be noticed and their magnetic nature means they can attach to, and blend in with, the vast majority of urban metallic structures such as benches, metal fences/railings and road signs.
Some geocache listing websites, such as Geocaching.com, don't have 'nano' as a size to select from when creating a cache listing, so geocachers are advised to list nano geocaches as 'micro', as they are less than 10 millilitres in volume [3] [7] [8]
Some geocachers believe that 'nano' should be a separate size to 'micro' due to their noticeable size difference, so use the 'other' or 'not specified' size option. [9]
Magnetic nanos are not completely weatherproof, even with an O-ring seal, and this can present some issues:
The paper log sheets inside nanos can sometimes become jammed and difficult to extract and roll back up, particularly if water has entered the nano. As a result, it is recommended that geocachers bring tweezers if they are finding nano caches and this is usually written on the geocache's webpage. [9] [4] Also, in cold conditions, if no rubber seal is present, then the nano can freeze and become difficult to open.
Geocaching is an outdoor recreational activity, in which participants use a Global Positioning System (GPS) receiver or mobile device and other navigational techniques to hide and seek containers, called geocaches or caches, at specific locations marked by coordinates all over the world. The first geocache was placed in 2000, and by 2023 there were over 3 million active caches worldwide.
Mu-metal is a nickel–iron soft ferromagnetic alloy with very high permeability, which is used for shielding sensitive electronic equipment against static or low-frequency magnetic fields.
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers.
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. Galvanometers work by deflecting a pointer in response to an electric current flowing through a coil in a constant magnetic field. The mechanism is also used as an actuator in applications such as hard disks.
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
The reed switch is an electromechanical switch operated by an applied magnetic field. It was invented in 1922 by professor Valentin Kovalenkov at the Petrograd Electrotechnical University, and later evolved at Bell Telephone Laboratories in 1936 by Walter B. Ellwood into the reed relay. In its simplest and most common form, it consists of a pair of ferromagnetic flexible metal contacts in a hermetically sealed glass envelope. The contacts are usually normally open, closing when a magnetic field is present, or they may be normally closed and open when a magnetic field is applied. The switch may be actuated by an electromagnetic coil, making a reed relay, or by bringing a permanent magnet near it. When the magnetic field is removed, the contacts in the reed switch return to their original position. The "reed" is the metal part inside the reed switch envelope that is relatively thin and wide to make it flexible, resembling the reed of a musical instrument. The term "reed" may also include the external wire lead as well as the internal part.
In electromagnetism, an eddy current is a loop of electric current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction or by the relative motion of a conductor in a magnetic field. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field. They can be induced within nearby stationary conductors by a time-varying magnetic field created by an AC electromagnet or transformer, for example, or by relative motion between a magnet and a nearby conductor. The magnitude of the current in a given loop is proportional to the strength of the magnetic field, the area of the loop, and the rate of change of flux, and inversely proportional to the resistivity of the material. When graphed, these circular currents within a piece of metal look vaguely like eddies or whirlpools in a liquid.
A steel can, tin can, tin, or can is a container made of thin metal, for distribution or storage of goods. Some cans are opened by removing the top panel with a can opener or other tool; others have covers removable by hand without a tool. Cans can store a broad variety of contents: food, beverages, oil, chemicals, etc.
Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid. Each magnetic particle is thoroughly coated with a surfactant to inhibit clumping. Large ferromagnetic particles can be ripped out of the homogeneous colloidal mixture, forming a separate clump of magnetic dust when exposed to strong magnetic fields. The magnetic attraction of tiny nanoparticles is weak enough that the surfactant's Van der Waals force is sufficient to prevent magnetic clumping or agglomeration. Ferrofluids usually do not retain magnetization in the absence of an externally applied field and thus are often classified as "superparamagnets" rather than ferromagnets.
Concealment devices or diversion safes are used to hide things for the purpose of secrecy or security. They are made from an ordinary household object such as a book, a soda can, a candle, a can, or something as small as a coin. The idea is that such an inconspicuous object would not be expected to contain anything of worth.
A geocoin is a metal or wooden token minted in similar fashion to a medallion, token coin, military challenge coin or wooden nickel, for use in geocaching, specifically as form of a calling card.
Nano, Nano-, NANO or NaNo may refer to:
Magnepan is a private high-end audio loudspeaker manufacturer in White Bear Lake, Minnesota, United States. Their loudspeaker technology was conceived and implemented by engineer Jim Winey in 1969.
An agitator is a device or mechanism to put something into motion by shaking or stirring. There are several types of agitation machines, including washing machine agitators and magnetic agitators. Agitators can come in many sizes and varieties, depending on the application.
A waste container, also known as a dustbin, rubbish bin, trash can, and garbage can, among other names, is a type of container intended to store waste that is usually made out of metal or plastic. The words "rubbish", "basket" and "bin" are more common in British English usage; "trash" and "can" are more common in American English usage. "Garbage" may refer to food waste specifically or to municipal solid waste in general.
Magnetic field viewing film is used to show stationary or slowly changing magnetic fields; it shows their location and direction. It is a translucent thin flexible sheet, coated with micro-capsules containing nickel flakes suspended in oil. When magnetic lines of force are parallel to the surface of the carrier sheet, the surfaces of the flakes are reflective, and appear bright. When lines of force are perpendicular to the sheet, the flakes are edge-on, and appear significantly darker. When the film is placed on a magnet's pole, the latter case applies.
An ammunition box or cartridge box is a container designed for safe transport and storage of ammunition. It is typically made of metal and labelled with caliber, quantity, and manufacturing date or lot number. A rubber gasket is commonly found in the hinged lid to protect the ammunition from moisture damage.
Dexter Industries is a company that designs robots for education, research, and personal use. The company makes several products that expand the LEGO Mindstorms, Raspberry Pi, and Arduino prototype systems.
GeoKrety is an online tracking service targeted at Geocachers. Each registered object, called a GeoKret, has a unique tracking code, allowing its movements between locations such as Geocaches to be tracked and registered on the service. While the idea behind trackable items such as GeoKrety originated with the geocoin and travel bug. Geokrety is an independent trackable service that can be used with any geocaching activity.
Robotic sperm are biohybrid microrobots consisting of sperm cells and artificial microstructures. Currently there are two types of spermbots. The first type, the tubular spermbot, consists of a single sperm cell that is captured inside a microtube. Single bull sperm cells enter these microtubes and become trapped inside. The tail of the sperm is the driving force for the microtube. The second type, the helical spermbot, is a small helix structure which captures and transports single immotile sperm cells. In this case, a rotating magnetic field drives the helix in a screw-like motion. Both kinds of spermbots can be guided by weak magnetic fields. These two spermbot designs are hybrid microdevices, they consist of a living cell combined with synthetic attachments. Other approaches exist to create purely synthetic microdevices inspired by the swimming of natural sperm cells, i.e. with a biomimetic design, for example so-called Magnetosperm which are made of a flexible polymeric structure coated with a magnetic layer and can be actuated by a magnetic field.