PTAB

IPR2021-01165

InductEV Inc v. Massachusetts Institute Of Technology

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Wireless Non-Radiative Energy Transfer
  • Brief Description: The ’734 patent relates to a system and method for wirelessly transferring electromagnetic energy between two coupled electromagnetic resonators. The technology relies on using high "quality factor" (Q-factor) resonators to enable efficient, non-radiative energy transfer over distances larger than the characteristic size of the resonators.

3. Grounds for Unpatentability

Ground 1: Obviousness over Stark - Claims 1-7, 13, 19-22, 25-26, 29-30, 33-34, 37-38, 41-42, 45-46, 49-50, 53-54, 57-61, 64, and 67-70 are obvious over Stark.

  • Prior Art Relied Upon: Stark (Joseph C. Stark, III, Wireless Power Transmission Utilizing A Phased Array Of Tesla Coils (2004)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Stark, a master's thesis, disclosed all elements of the challenged claims. Stark’s system used a "coupled resonant system" (a Tesla coil) with primary and secondary circuits that Petitioner mapped to the patent’s first and second "electromagnetic resonator structures." Petitioner asserted that Stark taught designing these resonators with specific resonant frequencies (ω) and quality factors (Q), including explicit disclosures of systems with Q-factors of 100 and 1,000. This was argued to meet the core limitation of independent claims 1 and 6 requiring Q-factors greater than 100. For dependent claims, Petitioner contended Stark’s teachings of Q=1,000 met higher thresholds (e.g., >200, >500), and that Stark’s prototype with movable coils taught the movability and distance limitations.
    • Motivation to Optimize: While a single-reference ground, Petitioner argued a Person of Ordinary Skill in the Art (POSA) would be motivated to implement Stark’s teachings to achieve high Q-factors. Stark itself explained that increasing Q-factors increases peak output voltage and energy transfer efficiency. Maximizing efficiency was presented as a fundamental and well-understood design goal for a POSA, providing ample motivation to select component values that would yield Q-factors well over 100 as taught by Stark.
    • Expectation of Success: Petitioner argued a POSA would have a high expectation of success, as Stark provided the complete theoretical framework, specific design formulas, and even MATLAB code for designing a high-Q resonant system. Achieving the claimed Q-values was presented as a predictable result of applying Stark's explicit teachings, not requiring undue experimentation.
    • Key Aspects: A key point was that Stark, though not cited during the ’734 patent’s U.S. prosecution, was successfully used to reject substantially similar claims in a corresponding European patent application.

Ground 2: Obviousness over Stark and Mecke - Claims 61, 62, 64, and 65 are obvious over Stark in view of Mecke.

  • Prior Art Relied Upon: Stark (as above) and Mecke (R. Mecke & C. Rathge, High frequency resonant inverter for contactless energy transmission over large air gap, IEEE Power Electronics Specialists Conference (June 2004)).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground focused on dependent claims requiring a transfer distance (D) greater than 1 cm (claims 61, 64) and greater than 30 cm (claims 62, 65). Petitioner asserted that Stark’s prototype, which operated at distances up to 10 inches (~25.4 cm), inherently disclosed a distance greater than 1 cm. To meet the >30 cm limitation, Petitioner combined Stark with Mecke. Mecke was argued to teach a similar inductive power system for applications like electric vehicle charging, explicitly disclosing operation over a "large air gap" of 30, 40, or even 80 cm.
    • Motivation to Combine: A POSA would combine Stark's high-Q resonant system with Mecke's teaching of large operating distances to create a system suitable for a broader range of practical applications. The motivation was to adapt Stark’s efficient transfer method for uses, such as vehicle charging, that require larger gaps than Stark's benchtop prototype, a problem explicitly addressed by Mecke.
    • Expectation of Success: Success was expected because Stark and Mecke described fundamentally similar inductive power systems with equivalent circuit models. A POSA would understand that modifying Stark's system to operate at larger distances, for example by using larger coils as suggested in the art, was a predictable design modification.

4. Key Technical Contentions (Beyond Claim Construction)

  • Inherent Nature of the Q-Factor Formula: A central contention was that the claimed relationship between quality factor, resonant frequency, and intrinsic loss rate (Q = ω / (2Γ)) is not an inventive feature but an inherent, textbook-level property of any RLC resonant circuit. Petitioner argued this formula is equivalent to other standard definitions of Q, and therefore, when a reference like Stark discloses a resonator with a given ω and Q, it inherently discloses the claimed relationship and the corresponding intrinsic loss rate Γ.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv was inappropriate. It contended that the parallel district court case was in its earliest stages, as Petitioner had not yet filed a responsive pleading, the court had not decided any substantive issues, and the parties' investment in the litigation was minimal. Petitioner asserted that these factors weighed heavily in favor of the Board reaching the merits of the petition.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-7, 13, 19-22, 25-26, 29-30, 33-34, 37-38, 41-42, 45-46, 49-50, 53-54, 57-62, 64-65, and 67-70 of the ’734 patent as unpatentable.