WiTricity Corp v. InductEV Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: WiTricity Corporation (Delaware)
  • Defendant: InductEV, Inc. (Delaware)
  • Plaintiff’s Counsel: Eckert Seamans Cherin & Mellot, LLC; Alston & Bird LLP
• Case Identification: 1:24-cv-00406, E.D. Pa., 03/21/2023
• Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Pennsylvania because Defendant maintains a regular and established place of business in the district and has committed alleged acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s wireless inductive charging systems for electric vehicles infringe four patents related to highly resonant wireless power transfer, foreign object detection, secure energy transfer, and high-power transfer under regulatory constraints.
• Technical Context: Highly resonant wireless power transfer is a foundational technology for the electric vehicle market, enabling convenient and automated charging for commercial fleets and consumer vehicles.
• Key Procedural History: The complaint alleges that Plaintiff put Defendant on notice of infringement as early as June 4, 2015, via a letter to Defendant’s predecessor, Momentum Dynamics, seeking to open licensing discussions. A renewed request was allegedly sent on November 16, 2020. These allegations of pre-suit knowledge form the basis for Plaintiff's claims of willful infringement.

Case Timeline

Date	Event
2008-07-08	’654 Patent Priority Date
2008-09-27	’687 Patent Priority Date
2008-10-27	’719 Patent Priority Date
2011-09-09	’184 Patent Priority Date
2013-06-11	’719 Patent Issued
2013-06-18	’654 Patent Issued
2014-12-16	’687 Patent Issued
2015-06-04	Plaintiff allegedly sends first notice letter to Defendant
2018-07-17	’184 Patent Issued
2020-11-16	Plaintiff allegedly sends renewed notice letter
2023-03-21	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,461,719 - "Wireless Energy Transfer Systems," issued June 11, 2013

The Invention Explained

• Problem Addressed: The patent describes the challenge of efficiently transferring power over mid-range distances (e.g., from centimeters to meters) without the physical contact and precise alignment required by traditional, non-resonant inductive coupling. (Compl. ¶12; ’719 Patent, col. 2:4-15).
• The Patented Solution: The invention uses a system of at least two "high-Q" magnetic resonators that are strongly coupled. A source resonator, powered by an external source, generates an oscillating, non-radiative magnetic field, and a device resonator captures energy from this field to power a load. The use of high-Q resonators allows for efficient energy exchange over distances larger than the size of the resonators themselves, with greater tolerance for misalignment. (’719 Patent, col. 2:16-32, col. 3:1-5).
• Technical Importance: This approach enabled practical wireless charging for applications like consumer electronics, medical implants, and electric vehicles, moving beyond the limitations of older, less efficient inductive technologies. (Compl. ¶12).

Key Claims at a Glance

• The complaint asserts independent claim 1. (Compl. ¶16).
• Essential elements of claim 1 include:
  • A source resonator having a Q-factor Q1 > 100 and a characteristic size x1, coupled to a power generator.
  • A second resonator having a Q-factor Q2 and a characteristic size x2, located a distance D from the source resonator.
  • The source and second resonators are coupled to exchange energy wirelessly.
  • The second resonator is coupled to a load.
  • The condition where the square root of the product of the Q-factors is greater than 100.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 10,027,184 - "Foreign Object Detection In Wireless Energy Transfer Systems," issued July 17, 2018

The Invention Explained

• Problem Addressed: Metallic or other foreign object debris (FOD) placed in the strong magnetic field of a wireless power transfer system can heat up, potentially causing burns, fire, or damage to the system or the object. (’184 Patent, col. 1:43-54).
• The Patented Solution: The invention provides a system for detecting FOD by measuring localized perturbations in the oscillating magnetic field. It employs magnetic field sensors, such as "gradiometers" formed from figure-8 loops of wire, which are designed to detect gradients or changes in the magnetic field caused by the presence of an FOD. These sensor readings can then be used by a control system to take action, such as shutting down power transfer. (’184 Patent, Abstract; col. 2:20-34).
• Technical Importance: FOD detection is a critical safety feature for high-power wireless charging systems, particularly in public or uncontrolled environments like parking spaces for electric vehicles. (’184 Patent, col. 1:5-14).

Key Claims at a Glance

• The complaint asserts independent claim 16, which is a method claim. (Compl. ¶27).
• Essential elements of claim 16 include:
  • Performing a health and/or status check of a source resonator.
  • Verifying that no foreign object debris has moved onto or over the source resonator.
  • Positioning a vehicle over the source resonator.
  • Verifying again that no foreign object debris has moved onto or over the source resonator.
  • Generating an oscillating magnetic field to transfer energy to the vehicle.
  • Verifying that no foreign object debris has moved onto or over the source resonator during the transfer of energy.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 8,912,687 - "Secure Wireless Energy Transfer For Vehicle Applications," issued December 16, 2014

• Patent Identification: U.S. Patent No. 8,912,687, "Secure Wireless Energy Transfer For Vehicle Applications," issued December 16, 2014. (Compl. ¶10).
• Technology Synopsis: The patent describes a system for secure wireless power transfer, wherein a vehicle-mounted resonator must be authenticated with the power source before energy transfer is initiated. This is accomplished via a communications channel, which can be in-band (using the power transfer field itself) or out-of-band, to ensure that only authorized devices receive power. (’687 Patent, Abstract).
• Asserted Claims: Independent claim 1 is asserted. (Compl. ¶37).
• Accused Features: The complaint alleges that the InductEV Inductive Charging System infringes this patent. (Compl. ¶37).

U.S. Patent No. 8,466,654 - "Wireless High Power Transfer Under Regulatory Constraints," issued June 18, 2013

• Patent Identification: U.S. Patent No. 8,466,654, "Wireless High Power Transfer Under Regulatory Constraints," issued June 18, 2013. (Compl. ¶11).
• Technology Synopsis: The patent addresses the need for high-power wireless charging systems to comply with regulatory limits on electromagnetic field exposure. The described system includes features for positioning the primary and secondary coils (e.g., vehicle guidance systems, movable coils) to achieve close coupling, which allows for efficient power transfer while maintaining the radiated H-field below specified safety limits. (’654 Patent, Abstract).
• Asserted Claims: Independent claim 13 is asserted. (Compl. ¶48).
• Accused Features: The complaint alleges that the InductEV Inductive Charging System infringes this patent. (Compl. ¶48).

III. The Accused Instrumentality

Product Identification

• The accused product is Defendant’s "Inductive Charging System." (Compl. ¶14).

Functionality and Market Context

• The complaint alleges the accused system includes high-power components such as "200kW bus ground side transmitters" and "200kW vehicle on-board charging receivers." (Compl. ¶14). The system is described as comprising a "ground assembly" that transfers power from the grid to in-ground pads and a "vehicle assembly" that receives the energy and transfers it to the vehicle's battery. (Compl. ¶14).
• The complaint asserts that Defendant markets these systems for commercial and transit vehicle fleets and has installed or proposed to install them for public bus networks in multiple U.S. cities. (Compl. ¶14, ¶15). It further alleges that Defendant has "more than twelve customers in service, with at least 63 ground assemblies and at least 95 vehicles in operation." (Compl. ¶15).

IV. Analysis of Infringement Allegations

The complaint references, but does not attach, claim chart exhibits detailing its infringement theories. (Compl. ¶16, ¶27, ¶37, ¶48). The analysis below is therefore based on the narrative allegations in the complaint.

’719 Patent Infringement Allegations

The complaint’s infringement theory appears to be that the InductEV system, by its fundamental operation, practices the claimed invention. The system’s "ground assembly" is alleged to be the claimed "source resonator," and the "vehicle assembly" is alleged to be the "second resonator" coupled to a load (the vehicle battery). (Compl. ¶14). The complaint alleges that these components are used to wirelessly transfer energy, thereby meeting the core elements of claim 1. (Compl. ¶16).

• Identified Points of Contention:
  • Technical Questions: A primary factual question for the court will be whether the accused InductEV system's resonators meet the specific numerical limitations of claim 1, namely a "Q-factor... > 100" and "√Q1Q2 > 100." The complaint does not provide specific technical data regarding the Q-factors of the accused products, making this a central evidentiary issue.

No probative visual evidence provided in complaint.

’184 Patent Infringement Allegations

The complaint alleges that InductEV's use of its charging system infringes the method of claim 16. (Compl. ¶27). The infringement theory is that the accused system necessarily performs the claimed steps of checking for foreign objects before, during, and after a vehicle is positioned for charging. This implies the accused system contains a safety or monitoring function that performs the claimed "verifying" steps. (Compl. ¶27).

• Identified Points of Contention:
  • Scope Questions: The infringement analysis may turn on the scope of the term "verifying." Does this term require a dedicated, active FOD detection subsystem that measures magnetic field perturbations, as described in the ’184 patent’s specification, or could it be construed more broadly to cover general system health checks that might indirectly signal an obstruction?
  • Technical Questions: A key evidentiary question will be whether the accused system actually performs the specific sequence of verification steps recited in claim 16: a pre-arrival check, a post-positioning check, and a continuous check during energy transfer. The complaint does not detail the specific operational logic of the accused system’s safety features.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

For the ’719 Patent:

• The Term: "a quality factor, Q, of greater than 100"
• Context and Importance: This term is the central technical limitation that distinguishes the claimed "highly resonant" system from prior art low-Q inductive systems. The definition of "Q-factor" and the methodology for its measurement will be critical to determining infringement, as the accused system must be shown to meet this specific numerical threshold.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claims provide a clear numerical floor ("greater than 100"), suggesting that any resonator that meets this performance metric, regardless of its specific construction, falls within the claim scope. The specification supports this by describing Q as a general characteristic of a resonator's efficiency. (’719 Patent, col. 11:32-41).
  • Evidence for a Narrower Interpretation: A defendant may argue that the term should be understood in the context of the specific embodiments disclosed, such as those using capacitively-loaded conductive loops made from specific materials (e.g., Litz wire) designed to minimize losses at high frequencies. (’719 Patent, col. 23:29-43).

For the ’184 Patent:

• The Term: "verifying that no foreign object debris has moved onto or over the source resonator"
• Context and Importance: This phrase appears three times in method claim 16 and defines the active safety monitoring steps of the invention. Whether the accused system performs an action that meets the definition of "verifying" will be dispositive for infringement of this patent. Practitioners may focus on this term because it implies an active, deliberate check rather than a passive state.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A plaintiff may argue "verifying" should be given its plain and ordinary meaning, covering any system check (e.g., a check of impedance, power draw, or other system parameters) that confirms the system is in a safe, unobstructed state ready for power transfer.
  • Evidence for a Narrower Interpretation: The specification consistently describes the detection and verification process as being accomplished through an active system of "magnetic field sensors and/or gradiometers" that "measure perturbations in the magnetic field." (’184 Patent, col. 2:21-24). A defendant may argue that "verifying" must be limited to this disclosed mechanism, not general system diagnostics.

VI. Other Allegations

• Indirect Infringement: For all four patents-in-suit, the complaint alleges induced infringement under 35 U.S.C. § 271(b) and contributory infringement under § 271(c). The allegations are based on Defendant allegedly instructing and encouraging its customers to use the Inductive Charging System in an infringing manner through product documentation and its website. (Compl. ¶18-23, ¶29-33, ¶39-44, ¶50-54). The complaint also asserts that the accused system is not a staple article of commerce and is not suitable for substantial noninfringing uses. (Compl. ¶22-23, ¶32-33, ¶43-44, ¶53-54).
• Willful Infringement: The complaint alleges that Defendant’s infringement of all four patents was and continues to be willful. The allegations are based on Defendant’s alleged pre-suit knowledge of the patents, stemming from notice letters sent on June 4, 2015, and November 16, 2020. (Compl. ¶17, ¶24, ¶28, ¶34, ¶38, ¶45, ¶49, ¶55).

VII. Analyst’s Conclusion: Key Questions for the Case

This dispute will likely focus on the technical operation of the accused systems and the specific language of the patent claims. The central questions for the court appear to be:

• A core issue will be one of evidentiary proof: As the complaint relies on incorporating by reference unattached claim charts, a primary question is whether discovery will produce technical evidence demonstrating that the accused InductEV systems meet the specific, quantitative requirements of the asserted claims, such as the Q-factor values recited in the ’719 patent.
• A key legal question will be one of definitional scope: The case may turn on the construction of the method-step term "verifying" in the ’184 patent. The court will need to decide whether the term requires the specific magnetic-field perturbation sensor system detailed in the patent's specification or if it can be construed more broadly to encompass other forms of system-level safety or status checks.
• A critical issue for damages will be willfulness: Given the complaint’s allegations of pre-suit notice dating to 2015, the court will likely examine the timeline and content of communications between the parties to determine when Defendant knew or should have known of its potential infringement and whether its continued conduct was objectively reckless.