Inside the Challenging Development of a Low-Friction Micropump

Why It Matters

The breakthrough enables high‑precision, single‑use wearable drug delivery at lower cost, accelerating time‑to‑market for therapies that depend on accurate micro‑dosing.

Key Takeaways

• Integrated LSR seal and PBT housing cut assembly steps by 15%
• In‑mold transfer tooling enabled 4‑cavity production of 4‑5 M units/year
• Friction‑modified self‑adhesive LSR provided simultaneous bonding and slip
• Pre‑distorting molds using CT data achieved micron‑level tolerances
• Cost per pump dropped ~20% versus traditional multi‑part assembly

Pulse Analysis

The wearable drug‑delivery market is racing to provide patients with discreet, on‑demand dosing of biologics, vaccines and chronic‑care medications. Conventional pumps rely on lubricants that risk contaminating sensitive formulations, forcing manufacturers to accept larger, more complex assemblies. Trelleborg’s 15 mm micropump confronts this dilemma head‑on, delivering 2‑10 µL per shot without any lubricant, a critical advantage for therapies where purity and dosing accuracy are non‑negotiable.

Achieving that performance required a two‑pronged engineering approach. First, a custom liquid silicone rubber (LSR) was formulated to self‑adhere to the polybutylene terephthalate (PBT) housing while presenting a slick surface to the moving plunger, eliminating the need for separate bearing materials. Second, the team embraced a data‑driven molding workflow: CT scans of early parts revealed up to 3 % LSR shrinkage, prompting iterative pre‑distortion of the mold cavity. This real‑world correction yielded micron‑level dimensional control that simulation alone could not guarantee, ensuring reliable sealing and ultra‑low friction across millions of units.

From a business perspective, consolidating the seal and housing into a single injection step reduced part count, lifted yield by roughly 15 %, and cut per‑unit cost by about 20 % compared with traditional multi‑part assembly. The solution scales through a four‑cavity, in‑mold transfer tool capable of producing four to five million pumps annually, positioning Trelleborg to meet growing demand for compact, high‑precision wearables. The methodology—material co‑design, tool pre‑distortion, and integrated molding—offers a template for other medical‑device makers confronting similar multi‑material, micro‑scale challenges.