Johns Hopkins mechanical engineer Tza-Huei (Jeff) Wang has been working for almost 20 years to bring sophisticated medical testing to a lab on a chip, making advanced screening techniques so portable that first-class healthcare could one day be taken anywhere, including rural areas lacking full-scale medical labs or hospitals.
Supported largely by funding from the National Institutes of Health, Wang's team develops small, inexpensive microfluidic devices that can diagnose diseases—from gonorrhea to esophageal cancer—using droplets of body fluid a tiny fraction of the size of a single human tear. This droplet is placed on a disposable chip the size of a USB thumb drive and inserted into a handheld machine, resulting in a diagnosis in under an hour—much faster than the days required for traditional lab analysis.
Wang, a professor of mechanical engineering at Johns Hopkins University's Whiting School of Engineering and a member of its Institute for NanoBioTechnology, believes this combination of portability and low overhead will bring fast, cost-effective testing to places where traditional labs aren't available, helping patients get answers and begin treatment in a single visit.
"Our vision is to bring lab-quality diagnostics to everyone, no matter where they live," Wang said. "These portable devices remove barriers to treatment and promise to dramatically improve health outcomes."
In 2018, Wang received a $5.1 million grant from the NIH to create a portable device that not only rapidly tests for gonorrhea but also detects if a specific bacterial strain is antibiotic resistant—a growing problem for public health. Knowing which bacterial strain is involved tells the doctor what medications are best suited to treat the case and the minimum amount needed.
"This allows for precision therapy for each case," said Wang, who worked on the project with Charlotte Gaydos, a professor emerita at the Johns Hopkins School of Medicine.
The team tested its microfluidic chip device in the Emergency Department at the Johns Hopkins Hospital and several clinics in Baltimore, as well as through a pilot program in rural Uganda. Since then, Wang's lab has launched a startup, Prompt Diagnostics, to commercialize this technology. In addition to sexually transmitted infections, the team is expanding its affordable diagnostic technologies to detect other diseases, such as HIV (via viral loading testing) and fungal infections.
Wang's lab is also developing the Automated Cartridge-based Cancer Early Screening System (ACCESS), an affordable, shoebox-sized device that detects various types of cancer from biomarkers in a small DNA sample. A key focus is esophageal cancer, a highly lethal disease requiring early detection. Wang is collaborating with Stephen Meltzer, a professor of medicine and oncology at the Johns Hopkins School of Medicine, to refine ACCESS for this use. The system screens for molecular signatures linked to the disease, which has a survival rate of 20% in developed countries and less than 5% in developing countries. Current detection methods—radiology, endoscopy, and biopsy—are often performed too late and require patient sedation and invasive techniques within well-equipped health care settings, limiting accessibility, according to Wang.
The team is currently refining the design and preparing for testing in clinics here and abroad.
In addition to using microfluidics for diagnosis, Wang has developed a robotic platform that promises to improve the success of antibiotic treatment. RoboDrop rapidly screens multiple combinations of antibiotics simultaneously to find the most potent mixtures against resistant bacteria. The team is now expanding testing to evaluate RoboDrop's ability to adapt to the different bacterial strains encountered in real-world settings.
"NIH support has been crucial in allowing us to transform these platforms from concepts developed in a laboratory to real-life solutions that promise to reach people where they need it the most," he said. "Without this sustained support, we could never tackle these life-saving technologies at this scale."
