Electromagnetic induction has diverse applications in modern technology. From computer devices to energy recovery systems, this phenomenon plays a crucial role in data storage, input devices, and improving vehicle efficiency.

The principles of electromagnetic induction extend to medical applications like transcranial magnetic stimulation. This non-invasive technique uses changing magnetic fields to induce currents in the brain, offering potential treatments for various neurological and psychiatric disorders.

Applications of Electromagnetic Induction

Magnetic induction in computer devices

• Hard drives utilize magnetic induction to store and retrieve data
  • Magnetic disks store data as tiny magnetized regions
  • Small electromagnets called read/write heads hover over the disk surface
  • Write process involves heads creating localized magnetic fields to magnetize specific disk regions representing binary data
  • Read process entails heads detecting magnetic fields of magnetized regions and converting them back into binary data
• Graphics tablets employ magnetic induction for precise input and drawing
  • Tablet contains a grid of wires generating a magnetic field
  • Stylus contains a coil that induces a current when moved through the tablet's magnetic field
  • Induced current determines stylus position, pressure, and tilt
  • Information is transmitted to the computer enabling accurate digital input and drawing (Wacom tablets, Apple Pencil)

Electromagnetic induction for energy recovery

• Electric and hybrid vehicles utilize regenerative braking systems to recover energy during deceleration
  • Electric motor acts as a generator when the vehicle brakes
  • Motor's rotor (typically a permanent magnet) spins within a stator (set of coils)
  • Spinning rotor induces a current in the stator coils via electromagnetic induction
  • Induced current recharges the vehicle's battery storing recovered energy for later use (Tesla Model S, Toyota Prius)
• Process improves overall vehicle efficiency by:
  • Reducing energy wasted during braking
  • Extending vehicle range on a single charge or tank of fuel
  • Reducing wear on traditional friction brakes as regenerative braking system handles a portion of the braking force
• Electromagnetic damping helps control unwanted oscillations in the system

Transcranial magnetic stimulation applications

• Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique utilizing electromagnetic induction
  • Strong, rapidly changing magnetic field generated by a coil placed near the patient's head
  • Magnetic field induces an electric current in the targeted brain region
  • Induced current can excite or inhibit neural activity depending on stimulation parameters (frequency, intensity, duration)
• Principles of TMS:
  • Faraday's law of induction: changing magnetic field induces an electric field
  • Induced electric field causes current to flow in brain tissue
  • Current alters membrane potential of neurons leading to changes in neural activity
• Uses of TMS:
  • Research: studying brain function, connectivity, and roles of specific brain regions
  • Diagnostics: evaluating integrity of neural pathways and identifying abnormalities
  • Treatment: alleviating symptoms of various neurological and psychiatric disorders
    1. Depression
    2. Anxiety
    3. Obsessive-compulsive disorder (OCD)
    4. Post-traumatic stress disorder (PTSD)
    5. Chronic pain (fibromyalgia, neuropathic pain)
    6. Parkinson's disease
    7. Stroke rehabilitation

Additional Applications of Electromagnetic Induction

• Transformers: devices that use electromagnetic induction to transfer electrical energy between circuits, often changing voltage levels
• Induction heating: process of heating an electrically conducting object by electromagnetic induction, used in industrial applications and cooking
• Magnetic resonance imaging (MRI): medical imaging technique that uses strong magnetic fields and radio waves to generate detailed images of the body's internal structures
• Hall effect: production of a voltage difference across an electrical conductor when a magnetic field is applied perpendicular to the current flow, used in various sensing applications
• Back EMF: induced voltage that opposes the change in current which created it, important in motor operation and control