Nested Coil Charging Surface for Multi-Device Wireless Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless charging technologies are limited by the need for precise alignment, costly amplifiers, complex synchronization, and inefficient sensing over large areas, leading to high costs and limited scalability, especially when charging multiple devices with varying sizes and types.

Innovation Solution

A network of nested sensing coils with active and passive coils, coupled to a controller, measures device interaction with magnetic fields to determine location and type, using machine learning algorithms for localization and tracking, and a software-defined network reconfigures impedance and resonance for efficient charging across large surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If isolated coil-based transmitters are used for wireless charging, then device charging is enabled, but the system requires hundreds of coils to cover large surfaces, dramatically increasing cost and complexity

Engineering Contradiction:
Improvecharging surface coverageVSAvoidnumber of coils and power management circuits
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Multiple coils are merged into a single transmitter unit with shared power management circuitry. The coils operate cooperatively under unified control, allowing large surface coverage to be achieved without proportionally increasing the number of independent power management circuits, thus reducing overall system complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The transmitter is designed with multi-functional capability to serve multiple devices simultaneously across a large surface area. A single transmitter unit can charge multiple devices of varying sizes and types by dynamically adjusting power distribution across its coil array, eliminating the need for dedicated transmitters for each device.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If Qi-based magnetic induction is used for wireless charging, then charging is enabled, but only few mm of alignment mismatch is permitted and effective at less than 5mm gap

Engineering Contradiction:
Improvecharging effectivenessVSAvoidalignment tolerance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The transmitter employs dynamic power distribution across its coil array, continuously adjusting which coils are active and their power levels based on real-time detection of device position and orientation. This dynamic adaptation allows the system to maintain effective charging across larger alignment tolerances compared to fixed single-coil systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The transmitter is divided into multiple coil segments that can be independently controlled. When a device is placed on the charging surface, the system activates only the relevant coil segments near the device, providing localized charging fields that maintain effectiveness even when the device is not perfectly centered or aligned.

Inventive Principle:
Principle #1Segmentation

3Power

If classical strongly coupled magnetic resonance energy transfer is used, then power can be delivered over 2m distance with more than 40% efficiency, but each coil needs its own separate power amplifier, explicit receiver-generated feedback, phase adjustment circuits and inter-coil synchronization

Engineering Contradiction:
Improvedeliverable power over distanceVSAvoidpower amplifiers and synchronization circuits
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

Multiple coils are combined into a unified transmitter system with shared power amplifiers and control circuitry. The coils are driven in a coordinated manner through a single control unit, eliminating the need for separate power amplifiers and synchronization circuits for each coil, thus maintaining high power delivery capability while reducing system complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Power

If MIMO-beamforming with six power amplifiers is used to deliver power through a table, then power delivery through obstacles is enabled, but each coil needs one amplifier which drives up cost

Engineering Contradiction:
Improvepower delivery through obstaclesVSAvoidnumber of power amplifiers
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The transmitter uses a smaller number of power amplifiers that can serve multiple coils in different configurations. The same power amplifiers can drive different coil combinations depending on the charging scenario, whether it's direct surface charging or power delivery through obstacles like tables, providing multi-functional capability without proportionally increasing amplifier count.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables cost-effective, scalable, and adaptable wireless charging over large areas, supporting multiple devices with varying sizes and types, reducing the need for individual amplifiers and complex synchronization, and allowing for customizable charging areas.

Implementation Method 1

measures device interaction with magnetic fields to determine location and type

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Implementation Method 2

wireless energy transfer to charge electronic devices

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

magnetic resonance-based energy transfer

Methodology Applied
Scientific EffectMagnetic resonance: Resonance

Data Source

PatentEP4042542B1Device sensing and charging using networked coils
Publication Date: 2026.02.11 NORTHEASTERN UNIV (US)
  • EP4042542B1 patent drawingFigure 1(a)~1(c)
  • EP4042542B1 patent drawingFigure 2
  • EP4042542B1 patent drawingFigure 3

AI summary

Sensing and charging of electronic devices using coils. A software-defined collaborative sensing approach can allow detection and location of multiple electronic devices with respect to a charging surface to allow for wireless charging thereof. Systems and methods can measure the interaction of devices with a generated magnetic field through a network of nested sensing coils that can sense the location of devices located around the network of coils based on their interaction with magnetic fields. Once the location of a device to be charged is determined, charging energy can be directed to the device based on its location on the charging surface. The charging surface can include one or more sensing nodes having a combination of nested active, or driven, and passive coils. These coils can be configured to transform existing two-dimensional (2D) surfaces or three-dimensional (3D) areas into a multi -device contactless wireless charger.