question: How are electronics made water resistant or waterproof, even when they have perforated or moveable parts (i.e. like a phone )?
comment: For total submersion you use parts that are sealed. The conductors of the connectors (charger, headphone jack) don't let water through. They use non corrosive metals like gold, which don't rust away when exposed to standing water. The phone itself is sealed using rubber o-rings that prevent water from entering through the gaps where the enclosure needs to be sealed. The speakers are connected to thin films that iirc are glued or otherwise sealed against the top of the enclosure so water doesn't enter the electrical area. There is some controversy over design decisions like the purported reason for Apple removing the headphone jack to make the iPhone water tight, which is kinda true because it removes a point of failure and kinda false because there were other reasons, like allowing more space on the PCB for them to increase the battery size, or making money from air pods. At the end of the day any feature as big as waterproofing requires so many changes to the enclosure and assembly that it drastically impacts every other aspect of the design.
passages: Waterproofing methods have been implemented in many types of objects, including paper packaging, cosmetics, and more recently, consumer electronics. Electronic devices used in military and severe commercial environments are routinely conformally coated in accordance with IPC-CC-830 to resist moisture and corrosion but encapsulation is needed to become truly waterproof. Even though it is possible to find waterproof wrapping or other types of protective cases for electronic devices, a new technology enabled the release of diverse waterproof smartphones and tablets in 2013. This method is based on a special nanotechnology coating a thousand times thinner than a human hair which protects electronic equipment from damage due to the penetration of water. Several manufacturers use the nano coating method on their smartphones, tablets, and digital cameras.
   Devices can face resistance to drops of up to 3m to concrete, fully sealed against dust and are submersible in up to 1.5 meter of water for up to 30 minutes, meeting IP68 certification requirements. The devices can operate in temperatures ranging from -20 °C to 60 °C, and are tested for resistance to impact, shock, vibration, altitude and extreme humidity.
   (STP9000, STP9100, STP9200)br
  
  In 2011, during trials for the London Olympics, TETRA radios were exposed to salt-laden environments, which were seen to quickly cause corrosion to connectors. In response to this and other new challenges, the STP9000 series drew on the ‘tough technology’ developed for the STP8X and went one step further, being designed to be not just waterproof, but fully submersible. It was resistant to heavy salt mist and included a new ‘Connector Protector’ technology that guarded it against direct exposure to salt water.
   The Nokia 8 has a 5.3-inch display and averages 7.3 mm thick and 4.3 mm thick at the edges. It is available in four colors: Polished Blue, Polished Copper, Tempered Blue, and Steel. The device features a full-length graphite-shielded copper cooling pipe that is designed to pull the heat away from the Snapdragon 835 chip and dissipate it across the full length and breadth of the smartphone. The phone is not water-resistant, but is IP54 splash-resistant.
  
  Section::::Specifications.:Hardware.
   Ericsson R310s
  
  The Ericsson R310s, produced by Ericsson Mobile Communications, now supported by Sony Mobile Communications, was a mobile phone produced in the early 2000s in a rugged body designed for use in environments or ways which might easily damage a standard handset.
  
  The outside of the body is reinforced with rubber inlays to withstand harsh treatment and to provide a good grip, preventing the phone from being slippery when wet.
  
  It is water resistant, the lid having silicone gaskets and membranes of GORE All-Weather material which prevented water from leaking in.
   Water resistance
  
  Water resistance may refer to:
  
  BULLET::::- The WR mark on a wristwatch indicating its ability to withstand exposure to water
  
  BULLET::::- The IP code on a mechanical or electrical enclosure indicating its ability to resist the ingress of water
  
  BULLET::::- Wet strength, a measure of the strength of paper when wet
  
  BULLET::::- Waterproofing, making objects or structures resist the ingress of water under specified conditions
  
  BULLET::::- Fluid resistance, drag in water
  
  BULLET::::- Lotus effect (water-resistance in plant leaves)
   iPhone 7 is rated IP67 water and dust resistant, although tests have resulted in malfunctions, specifically distorted speakers, after water exposure. The warranty does not cover any water damage to the phone.
  
  iPhone 7's home button uses a capacitive mechanism for input rather than a physical push-button, as on previous models, meaning direct skin contact (or a capacitive glove) is required to operate the device. Physical feedback is provided via a Taptic Engine vibrator, and the button is also pressure-sensitive. iPhone 7 retains the 3D Touch display system introduced on the iPhone 6S, providing pressure-sensitive touchscreen input.
   All iPhones (as well as many other devices by Apple) have a small disc at the bottom of the headphone jack that changes from white to red on contact with water; the iPhone 3G and later models also have a similar indicator at the bottom of the dock connector. Because Apple warranties do not cover water damage, employees examine the indicators before approving warranty repair or replacement. However, with the adoption of water resistance as a feature of the iPhone, this practice is no longer in use by Apple.
   Currently three manufacturers produce the mechanical mounting system (known as a substrate) which serves as the platform for attaching various components. Since the components are bolted to the surface of the substrate with sealing done by O-rings, they are sometimes referred to as surface mount devices. (The semiconductor industry has a related system; however the sealing is done by metallic seals rather than elastomeric O-rings.) There are currently over 60 different types of surface mount components available from various suppliers who provide valves, filters and regulators as well as pressure and flow sensing devices. Although the platform for mounting various components is common among the manufacturers, the interconnections below the surface are proprietary. The following figure shows three of the common designs. (From left to right) A Swagelok system which uses various lengths of tube connectors set in rigid channels; a CIRCORTech design which uses a single block with assorted flow-tubes; and a Parker Hannifin design which uses various blocks ported together with small connectors which also serve as flow paths.
   The LifeProof Nüüd is a technology that exposes the original screen of the device while protecting the phone from water, dirt, snow, and drop damage. This allows for zero visual interference, glare, loss of contrast or touch interference. The technology is currently supported on the iPhone 5, iPhone 5s, iPhone 5c, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7, iPhone 7 Plus, Galaxy S3, Galaxy S4, Galaxy S5, iPad, and iPad Mini.
   BULLET::::- TomTom Rider – Portable water-resistant models for motorcycle and motorscooter users. They differ from other devices in that the Rider is partly shielded and has a 'glove-friendly' screen and GUI. There are many different models in the NAV2 and NAV4 ranges.
   Section::::Non-hazardous locations.:Types 6, 6P.
  
  Over and above the safety offered by type 4 units, these have a much higher resistance to water even when there are chances of temporary immersion. It prevents the entry of water and keeps hazardous consequences at bay in case of prolonged immersion.
  
  Section::::Non-hazardous locations.:Types 12, 12K.
   The key feature of the phone is waterproof and dustproof, having an IP rating of IP65 and IP68. It is Sony’s first smartphone to feature an octa-core processor and also Sony’s first water-resistant smartphone to feature an exposed micro USB port (cap-less microUSB charging).
  
  Section::::Specifications.
  
  Section::::Specifications.:Hardware.
   Marine electronics
  
  Marine electronics refers to electronics devices designed and classed for use in the marine environment on board ships and yachts where even small drops of salt water will destroy electronics devices. Therefore, the majority of these types of devices are either water resistant or waterproof.
  
  Marine electronics devices include chartplotter, marine VHF radio, autopilot and self-steering gear, fishfinder and sonar, marine radar, GPS, fibre optic gyrocompass, satellite television, and marine fuel management.
  
  Section::::Communication.
   A water block is the watercooling equivalent of a heatsink. It can be used on many different computer components, including the central processing unit (CPU), GPU, PPU, and Northbridge chipset on the motherboard. It consists of at least two main parts; the "base", which is the area that makes contact with the device being cooled and is usually manufactured from metals with high thermal conductivity such as aluminum or copper. The second part, the "top" ensures the water is contained safely inside the water block and has connections that allow hosing to connect it with the water cooling loop. The top can be made of the same metal as the base, transparent Perspex, Delrin, Nylon, or HDPE. Most newer high-end water blocks also contain mid-plates which serve to add jet tubes, nozzles, and other flow altering devices.
   The Omate TrueSmart is IP67 certified and dustproof. However water damages are not covered by the warranty as long as the device can be opened to insert a SIM card, a SDcard or to replace the battery. The case is steel alloy or aluminum based, the glass is protected by a sapphire crystal coating, the straps are silicone. The straps are not replaceable since the GSM and GPS antennas are integrated into them. Measurements are 45mm × 45mm × 14mm.
  
  Section::::Specifications.:Connectivity.
   The device body is made of a material called "Liquidmorphium" which is described by the manufacturer as an “unbendable” metal that's stronger than titanium or steel and more resistant to shock and screen breakages.
   In general a vest's textile material temporarily degrades when wet. Neutral water at room temp does not affect para-aramid or UHMWPE but acidic, basic and some other solutions can permanently reduce para-aramid fiber tensile strength. (As a result of this, the major test standards call for wet testing of textile armor.) Mechanisms for this wet loss of performance are not known. Vests that will be tested after ISO type water immersion tend to have heat sealed enclosures and those that are tested under NIJ type water spray methods tend to have water resistant enclosures.
   LifeProof combines many technologies to create a case that protects electronic devices from the inside out. The case will make the phone waterproof, dirtproof, snowproof, and shockproof. LifeProof's case for Apple iPhones only adds to the sides of the phone. The case combines a polycarbonate frame, waterproof acoustic ports, a waterproof screen protector that is still fully touch sensitive, and a built-in optical glass that covers over the phone's camera lenses to prevent loss of photographic detail. Every LifeProof case is put together in a two-part snap-together assembly that has a thin polymer gasket where it closes. Each case then becomes fully waterproof after sealing, and also seals the charging port via a hinged, gasketed door.
   BULLET::::- Resistance to salty water. The watches under test shall be put in a 30 g/l NaCl (sodium chloride) solution and kept there for 24 hours at 18 to 25 °C. This test water solution has salinity comparable to normal seawater. After this test, the case and accessories shall be examined for any possible changes. Moving parts, particularly the rotating bezel, shall be checked for correct functioning.
   A new class of miniature wireless devices called motes are networked wireless sensors. Wireless sensor networking, WSN, makes use of miniaturization made possible by advanced IC design to couple full wireless subsystems to sophisticated sensors, enabling people and companies to measure a myriad of things in the physical world and act on this information through IT monitoring and control systems. These motes are completely self-contained, and will typically run off a battery source for years before the batteries need to be changed or charged.
   Apple did not explicitly market the first generation Apple Watch as being waterproof, stating that it can withstand splashes of water (such as rain and hand washing), but does not recommend submersion (IPX7). However, external testing by The Iconfactory and others revealed that Apple Watch can function when submerged in various conditions (such as swimming), although its touchscreen experiences "erratic" behavior when submerged.
  
  Apple introduced a high level of water resistance with the release of the Apple Watch Series 2, and the device was explicitly advertised as being suitable for swimming and surfing.
  
  Section::::Specifications.:Hardware.
  
  Section::::Specifications.:Hardware.:First generation.
   The beanbag-like design of the waterbag changes shape and conforms to a surface thus it collapses and is "slow acting" on impact. There is a significant difference between the physics of the sealed waterball and the water absorbing waterball or waterbag.
   Contact "carriers" which hold the parts of a connector together are usually made of plastic due to its insulating properties, and "housings" or "backshells" can be made of molded plastic or metal.
  
  Section::::Physical construction.:Failure modes.
  
  The majority of connector failures result in intermittent connections or open contacts:
   Water resistance is achieved by the gaskets which forms a watertight seal, used in conjunction with a sealant applied on the case to help keep water out. The material of the case must also be tested in order to pass as water resistant.
  