Our cash requirements and expenses continue to be significant. For the year ended December 31, 2023, we used $2,365,000 cash in operations, and at December 31, 2023, we had working capital of $3,652,000, and current assets of $6,362,000. In order to become profitable, we must significantly increase our revenues. Although our revenues are increasing through sales of our private-label products and from our engineering division, we expect to continue to use cash for the foreseeable future as it becomes available, and expect to continue to need to sell our securities to fund operations.
Our auditor's report for the year ended December 31, 2023, includes an explanatory paragraph in their audit opinion stating that our recurring losses from operations and working capital deficiency raise substantial doubt about our ability to continue as a going concern. We do not currently have sufficient financial resources to fund our operations or those of our subsidiaries. Therefore, we need additional financing to continue these operations.
We have relied on private securities offerings, as well as sales of stock to Lincoln Park Capital Fund, LLC ("Lincoln Park"; see Part II, Item 9B), to provide cash needed to close the gap between operational revenue and expenses. Our ability to rely on private financing may change if the United States enters a recession, if the Dow Industrial Average or Nasdaq composite decline significantly, if interest rates rise, if real estate values decline, if international events affect the global economy, or many other factors that impact private investors' willingness to invest in high-risk companies. Thus, while we have been able to rely on private investments in the past, we may not be able to do so in the near future.
During the year ended December 31, 2023, we received net proceeds of $4,600,000 through sales of our securities, both directly and through our subsidiaries. These sales are dilutive to our existing stockholders, and the stockholders of our subsidiaries. We intend to continue these financing activities, and thus intend to continue to dilute existing and future stockholders.