Financing the Region: How Sparkasse Aachen Supports DeepTech Startups Such as Membion

Thanks to RWTH Aachen University, Aachen is one of Germany's leading locations for startup spin-offs and startup support. Yet between a good idea and a successful business often lies one decisive challenge: financing. DeepTech and Cleantech startups in particular require substantial initial investment, long development cycles and financing partners who are willing to share technological risks. How such financing can succeed is demonstrated by the example of the startup Membion from the Aachen city region. The company develops innovative membrane filtration technologies for industrial wastewater treatment and has been supported by Sparkasse Aachen throughout its growth journey.

Confidence in the Future

Membion is headquartered in Roetgen, while its production facilities and offices are located in Monschau. The startup develops hollow fibre membranes that clean industrial and municipal wastewater more efficiently while significantly reducing the energy consumption of existing treatment plants. The technology addresses key challenges of the future, including water scarcity, resource efficiency and industrial sustainability.

For Sparkasse Aachen, it was precisely this combination that proved decisive.

“An innovative, sustainable product that is market-ready and has already demonstrated its value in real-world applications. Equally important was the entrepreneurial personality. The founders are passionate about their company, work in a highly cooperative manner and are always completely transparent,” summarises Jürgen Frank, Corporate Client Adviser at Sparkasse Aachen.

Financing technology-driven startups differs significantly from financing established SMEs. While banks can often rely on annual financial statements and many years of business performance when assessing established companies, they must place much greater emphasis on future potential when evaluating startups.

“With startups, it is essential to develop a deep understanding of the business model and assess whether it is needed and will be accepted by the market,” says Frank Mäutner, Director of Corporate Clients at Sparkasse Aachen. “That requires a great deal of confidence in the future and in the entrepreneurial personality.”

When Traditional Bank Financing Is Not Enough

DeepTech and Cleantech startups in particular often face a structural challenge: in their early stages, they are not yet bankable. This means they do not initially meet the requirements for traditional bank financing because they have not yet generated positive cash flows and are therefore often unable to cover interest payments and loan repayments from their own resources during the initial phase.

This is where complementary financing instruments such as the S-UBG Group and the TechVision Fund come into play. S-UBG is a regional investment company of the Sparkassen Finance Group in the western Rhineland and manages the TechVision Fund, which supports technology-driven startups through equity financing, thereby enabling them to build market-ready businesses in the first place. The current TechVision Fund provides around €55 million in initial capital for the startup ecosystem as well as for subsequent financing rounds (Series A/B) of its existing portfolio companies.

“Equity, promotional loans and additional risk-bearing partners provide the financial foundation that founders need,” explains Frank Mäutner.

Sparkasse Aachen works closely with funding institutions such as KfW, NRW.BANK, Bürgschaftsbank, as well as regional innovation networks. This was also the case for Membion, as explained by Dr Klaus Vossenkaul, founder of Membion:

“Together with Sparkasse Aachen, we structured our growth financing to match our specific needs. Funding programmes and grants were combined in the best possible way. Sparkasse Aachen was able to draw on its network, including its strong connections with NRW.BANK. Our principal bank also found effective ways to bring additional guarantors on board, enabling us to take the next major step,” says Vossenkaul.

“Not only in Membion's case, this creates a financing mix consisting of equity, promotional loans, public grants, equity investment and traditional bank financing,” explains Corporate Client Adviser Jürgen Frank.

Financing Requirements for Startups

When making financing decisions, Sparkasse Aachen looks beyond financial figures and business plans alone.

“A viable business model, realistic capital requirements, market and competitive analyses, technological relevance, and a convincing founding team all play a role in our financing decisions,” explains Irmgard Breidenich, Credit Advisory Specialist at Sparkasse Aachen.

“The right entrepreneurial personality is another key prerequisite for a successful business,” emphasises Frank Mäutner. “This is why personal conversations play a central role from an early stage. We can therefore recommend that all founders get in touch with Sparkasse Aachen as early as possible—ideally while they are still developing their business concept. Many startups underestimate both the length of the startup phase and the actual amount of capital required,” adds Breidenich.

Depending on the industry, the journey from the initial idea to implementation can take between six and twelve months. Early discussions help establish appropriate financing structures and avoid the need for adjustments at a later stage.

Regional Innovation as a Competitive Advantage

For Sparkasse Aachen, financing startups is about more than simply providing capital. The aim is to ensure that innovation and value creation remain in the region over the long term. Membion is a prime example of the impact this approach can have.

“We are creating new jobs in a region that is undergoing profound structural change, while making productive use of existing commercial properties in Monschau,” says Vossenkaul.

Established companies, universities and industrial partners also benefit from the founders' expertise. Networks such as Gateway Factory and competitions such as AC² play an important role in this process. Membion won the AC² Innovation Award for the Aachen region in 2025, gaining additional visibility as a result. While such an award does not automatically guarantee financing for Sparkasse Aachen, it does signal technological relevance and market potential.

The Aachen Region Offers Ideal Conditions

Today, the Aachen region benefits from a closely connected innovation ecosystem comprising universities, accelerators, investors, funding institutions and banks. It is through the collaboration of these organisations that technology-driven startups are able to grow internationally without having to leave the region.

For Frank Mäutner and Irmgard Breidenich, the conclusion is clear: “With our support, every founder in Aachen can find the right contact for their individual situation.”

They believe that this network is one of the region's greatest competitive advantages. For technology-driven startups such as Membion, it is essential. Success in Aachen is not built on an isolated bank loan, but on a collaborative ecosystem that combines equity and debt financing, technological expertise, public funding and strong regional cooperation.