Bought In A Lot Of 1,900 Patents. Lapsed For An Unpaid $1,600.

ALEXANDRIA, Virginia — The fee was $1,600.

That is the whole of the burial. On 16 June 2017 the grace period ran out on the second maintenance fee for United States Patent 7,548,412, nobody paid it, and the most frequently cited example of a suppressed energy patent fell into the public domain — where it has sat, free for anybody in the world to build, for nine years.

Nobody has built it. So we did.

The chain everybody describes

The chain is real, and the version told about it is not wrong about a single transfer.

Halvard Achterberg-Musa worked on laminated capacitor electrodes from 1996, in a rented unit outside Utica, with one employee. He filed in March 2003 and the patent granted in June 2009: a stacked electrode claiming 38 watt-hours per kilogram, against roughly nine for anything you could buy that year.

His company was wound up in 2011. A court-appointed receiver listed the patent as asset 214. In 2012 it was bought by Northmark IP Trust, a defensive aggregator whose subscribing members included three of the largest lithium-cell manufacturers in the world.

Inventor, receiver, industry. That is the story as it is normally told, and every link in it is documented in the recorded assignments, which we have published.

What the assignment record does not say

It does not say what Northmark paid, because assignments do not carry prices.

Northmark's own bankruptcy docket does. Lot 2012-14: 1,900 patents, $3,192,000, an average of $1,680 each.

The lot's acquisition diligence log is exhibit 44-C. It is eleven pages. It lists eleven patents pulled out for technical review by a named attorney, with dates and initials.

Asset 214 is not one of the eleven. It appears once in the entire Northmark record, on the schedule of assets acquired, as a number and a title.

No board paper mentions it. It was never licensed, never asserted, never offered to a member, never valued separately. We asked the former head of acquisitions directly whether any human being at the company had read the specification. Her answer is printed below and it is no.

What a renewals rule is

In 2016 the second maintenance fee came due. Northmark did not decide to abandon the patent. There was no meeting.

There was a rule, written down, in the same exhibit: at each maintenance window, drop anything carrying no forward citations, no assertion history and no member request. Four hundred and twelve patents went out of the portfolio that cycle. A renewals contractor executed the list. The invoice line for asset 214 reads $1,600 and it was never raised.

We had it built

Because the patent lapsed, anybody may build it. We wanted to know whether that mattered.

We sent the complete file — claims, drawings, the two examiner actions — to a university materials group under Dr. Anneke Ferreiro-Baptiste, with $18,600 and no context at all. They were not told where it came from, who had owned it, or what anybody had ever claimed about it. They were told to build what the document describes and to cycle it.

They built it twice.

The best cell reached 15.6 watt-hours per kilogram: 41 per cent of the claimed figure, and still respectable against the shelf of 2009. It then delaminated, comprehensively, at 600 cycles. The layer separation is visible in the report's photographs without magnification.

That report is published entire, including the first attempt, which failed at 140 cycles for reasons the group attributes to their own press.

The 1998 entry

Ruth Achterberg-Musa kept her husband's notebooks in a cupboard for fifteen years, and drove them ninety miles to us in a hotel car park because we asked her to.

Four of the seven survive. In the third, dated 14 September 1998, four and a half years before he filed, he writes out the delamination problem, sketches the shear at the layer boundary, and puts down two possible fixes.

Underneath, in the same pen: A year on this, probably less.

He died in November 2010, seven months before the receiver was appointed. His widow says he was still on it.

What this desk takes from it

There is no burial here. There is a receiver's schedule, a bulk purchase, a scoring rule and an unpaid invoice, and every step of it was somebody doing their job correctly at a price that made sense to them.

What the desk cannot get past is the nine years since. The document has been free to anybody with a printer since June 2017, and in that time the number of people who have attempted to build it appears to be one, and we paid them.

The suppression everybody argues about lasted five years and cost $1,680. The silence afterwards was free, and it is still going on.