Self-healing elastomer system

Patent US-7569625-B2 — Self-healing elastomer system

Patent number	US-7569625-B2 — Granted 2009
Assignee	THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS
Inventors	KELLER MICHAEL W.\|SOTTOS NANCY R.\|WHITE SCOTT R.
Forward citations	68
Patent family	3 in 2 countries
CPC	B29L, C08J, C08L, C08G, Y10T

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About this patent

US-7569625-B2 covers a self-healing elastomer composite — specifically a material engineered to autonomously repair cracks. Claim 1 defines a composite with four concrete elements: (1) a solid elastomer matrix made of a first polysiloxane; (2) a plurality of "first capsules" containing a polymerizer for a second polysiloxane; (3) a plurality of "second capsules" containing the corresponding activator for that polymerizer; and (4) a specific polymerizer chemistry — a mixture of hydroxyl-terminated polydimethylsiloxane and polydiethoxysiloxane. The mechanism is microencapsulation-based: when a crack propagates through the elastomer, it ruptures the embedded capsules, releasing the polymerizer and activator, which react to form a new polysiloxane that seals the damage. Dependent claims narrow the matrix to poly(dimethyl siloxane), the activator to amine or metal-salt catalysts, and add an optional silane adhesion promoter.

The patent is assigned to The Board of Trustees of the University of Illinois and names Michael W. Keller, Nancy R. Sottos, and Scott R. White — the Illinois group that is widely recognized as the originator of the microcapsule self-healing materials field. It was granted in 2009. The family is small at 3 members across 2 countries, indicating focused rather than aggressive international prosecution — consistent with a university filing that protects a core research result in key jurisdictions rather than broadly. It carries 68 forward citations, a substantial count for a chemistry/materials patent and a marker that the work seeded considerable downstream development.

Where this patent stands: This is an anchor-class filing rather than a niche refinement. It is one of a tightly knit cluster of University of Illinois patents (see US-6518330, US-7723405, US-7612152, US-7566747, US-9415575) that collectively define the microencapsulated self-healing polymer field, with US-6518330 (147 citations) serving as the foundational parent concept and this patent extending it specifically to soft elastomeric/polysiloxane matrices with a defined dual-capsule chemistry. Its importance lies less in any single product and more in its role as a portfolio cornerstone — the kind of academic IP that underpins licensing programs and that downstream industrial players (Motorola, HRL, Freudenberg) built upon. The 68 citations confirm it functions as prior art and a reference point across the field rather than as a defensive continuation.

Citing patents (68)

Patents that cite this one (forward citations)

DE-102008054122-B4 · US-9605162-B2 · US-2010206088-A1 · US-8236914-B2 · US-10508204-B2 · US-9816189-B2 · US-2011173971-A1 · US-11155940-B2 · US-2011097542-A1 · US-9119774-B2 · US-2006142406-A1 · US-2017218574-A1 · US-8962730-B2 · US-2011071234-A1 · US-9415575-B2 · US-10988626-B2 · US-8685513-B1 · US-8683798-B2 · US-2022056809-A1 · US-8703285-B2 · US-9988746-B2 · US-9267279-B2 · US-8383697-B2 · US-8846404-B2 · US-10724183-B2 · US-2007166542-A1 · US-10364534-B2 · US-10934669-B2 · US-10907018-B2 · US-9943487-B2 · US-2011003159-A1 · US-9550855-B2 · US-11186959-B2 · JP-2011089388-A · US-2010075134-A1 · US-9527982-B2 · US-11136675-B2 · US-2008173382-A1 · US-9136558-B2 · US-8920879-B2 · US-11168220-B2 · US-2009191402-A1 · US-10844185-B2 · US-9108364-B2 · US-9694629-B1 · EP-3495053-A1 · US-9951221-B2 · US-2011039980-A1 · US-10179846-B1 · WO-2014149741-A1 · US-10865306-B2 · US-8877309-B1 · US-7723405-B2 · US-10081715-B2 · US-2012196373-A1 · US-9533469-B2 · US-2011000733-A1 · US-2009115142-A1 · US-11543322-B2 · US-11702948-B2 · US-2011064997-A1 · US-2008305343-A1 · WO-2015130802-A1 · US-8088015-B2 · US-10011149-B2 · US-2010331445-A1 · US-10392713-B2 · WO-2012127418-A1

Cited patents (97)

Patents this one cites — its references (backward citations) — showing 96 of 97

US-6518330-B2 · US-6527849-B2 · US-4380617-A · US-6669961-B2 · US-5958325-A · US-2006111469-A1 · US-6808461-B2 · EP-0669368-A1 · US-5312940-A · US-4943621-A · US-6261360-B1 · WO-9955794-A1 · WO-9955753-A1 · US-4853434-A · US-2005038173-A1 · US-5789494-A · US-6048488-A · US-7192993-B1 · EP-0349855-A2 · US-5427880-A · US-6001909-A · US-4708969-A · US-6858659-B2 · WO-9620235-A1 · WO-9616100-A1 · US-5561173-A · DE-1590958-A1 · US-5413924-A · WO-9725360-A1 · US-6100323-A · US-7022179-B1 · US-5063103-A · US-3069370-A · US-2006252852-A1 · US-7276252-B2 · US-2002007959-A1 · EP-0424833-A2 · US-4940645-A · US-4080238-A · US-5643764-A · US-6075072-A · US-6388865-B1 · US-5504176-A · US-4301306-A · WO-2004035644-A2 · US-6040363-A · EP-0287288-A1 · WO-02064653-A2 · WO-2007082153-A2 · WO-2007143475-A1 · US-4804427-A · US-3868199-A · US-4324717-A · US-6224793-B1 · US-2004055686-A1 · US-2005250878-A1 · US-5801033-A · WO-2005118703-A1 · WO-9000005-A1 · US-7045562-B2 · EP-1168372-A1 · US-4755588-A · US-6287992-B1 · DE-10157123-A1 · US-5324616-A · EP-0985737-A1 · US-6113728-A · US-2002111434-A1 · US-4389496-A · US-6316194-B1 · US-2007282059-A1 · US-5550044-A · US-2004007784-A1 · WO-9320111-A2 · US-5575841-A · US-4461854-A · US-2006281834-A1 · EP-0020123-A1 · US-6235856-B1 · US-4902560-A · US-5185108-A · US-5660624-A · US-5840238-A · US-6479167-B2 · US-6258870-B1 · WO-9947704-A1 · US-3041289-A · US-5342909-A · US-5803963-A · US-2005085564-A1 · US-6599633-B1 · US-4758400-A · US-5989334-A · WO-2007009280-A1 · US-2007166542-A1 · DE-4209031-A1

Family members (3)

Related filings for the same invention across jurisdictions.

Publication	Country	Kind	Filed	Status
US-2007282059-A1 (priority)	US	A1	2006	PENDING
US-7569625-B2 (priority)	US	B2	2006	GRANTED
WO-2007143475-A1 (priority)	WO	A1	2007	PENDING

Patent landscape

The surrounding space splits into two distinct clusters. The nearest, most on-point patents are dominated overwhelmingly by The Board of Trustees of the University of Illinois, which authored 6 of the closest 6 self-healing materials filings (entries 1–6) — yet Illinois does not appear in the TOP_ASSIGNEES citation chart at all, because that chart is led by surgical and biomaterials companies whose patents pull far higher citation counts. The chart-leading assignees — Ethicon Inc (2,920 citations), Ethicon LLC (1,996), Biomerix Corporation (1,950 across 4 patents), and Cohesion Technologies — sit in the adjacent medical/elastomeric-implant cluster (tissue compensators, sealants, reticulated matrices) and are only loosely related to the capsule-based self-healing mechanism of the subject patent. In short, Illinois dominates the technically relevant neighborhood while the citation chart reflects a separate, higher-volume medical-device corpus.

Closest related patents:

US-6518330-B2 — Multifunctional autonomically healing composite material (Univ. of Illinois · 147 citations · 9-member family). The foundational microcapsule self-healing patent from the same group; the subject patent is effectively its elastomer-specific extension.
US-7723405-B2 — Self-healing coating system (Univ. of Illinois · 70 citations · 5-member family). A sibling filing applying the same dual-component capsule concept to coatings rather than bulk elastomers.
US-7108914-B2 — Self-healing polymer compositions (Motorola Inc · 69 citations · 8-member family). An industrial player's parallel approach to self-healing polymers, indicating the concept moved beyond academia.
US-2009247694-A1 — Self-healing elastomer system (Carl Freudenberg KG · 17 citations · 3-member family). A near-identically titled commercial filing from a major sealing/elastomer manufacturer, directly addressing the same application target.
US-9119774-B2 — Self-healing dental restorative formulations (Premier Dental Products · 3 citations · 2-member family). A recent, lightly-cited but tightly on-point application of capsule self-healing to a dental niche — strategic IP the citation-weighted score under-rewards.

Because the relevant chemistry leadership is academic (the University of Illinois cluster), licensing access to that portfolio matters as much as freedom-to-operate analysis for anyone building in this space. The field is tightly clustered around materials chemistry: Sterilization & Wound Care (A61L) is the single most concentrated subclass at 52.5× the corpus baseline, with Polymer Additives (C08K) at 31.5×, Polymer Compositions (C08L) at 29.7×, and Polymer Processing (C08J) at 23.1× — confirming a densely packed polymer/biomaterials neighborhood rather than a diffuse one.