On-Chip Processor: First Step in Point-of-Care Asthma &Tuberculosis Diagnostics

Source: Penn State University, by Walt Mills (July 30, 2015). AI-generated summary by biochip.com, published April 25, 2026. Not independently reviewed.

Penn State engineers and collaborators have built an on-chip sputum liquefier, a small device that uses ultrasonic waves to mix and prepare mucus samples for analysis. The device addresses what the team calls the first and most difficult step in creating a low-cost, point-of-care system for pulmonary diseases including asthma and tuberculosis. Sputum is thick, sticky material coughed up from the lungs, and it must be liquefied before clinicians can study the cells it contains. Rather than moving a potentially infectious sample among several laboratory instruments, the proposed lab-on-a-chip system would keep it in one disposable component. The acoustofluidic device, developed by researchers at Penn State with the National Heart, Lung, and Blood Institute and Washington University School of Medicine, uses 100 times less sample than conventional processing while providing equivalent accuracy. That reduction could matter for patients who struggle to produce large sputum samples. The team envisions a platform that a nurse could run with a few button presses, and potentially one that patients could use at home. A flow-cytometry component to identify cells and inflammation types was still under development when the liquefier was reported in Lab on a Chip.

Turning Thick Sputum Into a Testable Sample

Think of sputum preparation like breaking up a clump of hardened flour before it can be mixed evenly into dough. If the material remains thick and uneven, cells inside it are difficult to analyze reliably. The Penn State device uses acoustofluidics, the use of sound waves to move or manipulate liquids, to liquefy the sample inside a small chip.

Ultrasonic waves are sound vibrations at frequencies above human hearing. In this device, those vibrations provide the mixing action needed to process sputum without relying on the multiple separate machines used in conventional analysis. Tony Jun Huang, a professor of engineering science and mechanics at Penn State, developed the technology with his group.

Why Lung Samples Matter

Huang said pulmonary disease testing needs to examine cells directly from the lungs rather than rely only on blood samples. That distinction is particularly important in asthma, because patients can have different forms of airway inflammation and may respond to different drugs. An immunophenotype is the identifying pattern of immune-cell features that can help distinguish those forms.

The intended diagnostic system would analyze sputum cells to determine the type of inflammation in an asthma patient’s lungs. Stewart J. Levine, senior investigator and chief of the Laboratory of Asthma and Lung Inflammation at NHLBI, said that information could help health care providers individualize treatment. The same approach could also support sputum analysis for tuberculosis, a contagious lung infection that remains widespread in some regions.

A Smaller, Contained Workflow

Conventional sputum analysis presents a practical and safety challenge because specimens may carry infectious organisms and must be handled across several discrete instruments. A lab-on-a-chip approach puts multiple preparation steps into a compact device, much as a single appliance can replace several kitchen tools. Keeping the biospecimen in one disposable component could reduce handling while simplifying the workflow.

The team reported that its liquefier requires 100 times less sputum than the standard system while retaining equivalent accuracy. That is a concrete advantage for people unable to provide a large sample, a common hurdle in sputum-based testing. The proposed disposable portion of the device was expected to cost less than one dollar to manufacture.

From Sample Preparation to Cell Analysis

Liquefying sputum is only the opening stage of the planned diagnostic process. Po-Hsun Huang, a graduate student in the Huang group and first author of the Lab on a Chip paper, said colleagues were developing the system’s flow cytometry component. Flow cytometry is a method that examines individual cells as they pass through an instrument, allowing researchers to sort or identify cells by their measurable properties.

Combining liquefaction and flow cytometry on one platform could turn raw sputum into a readout without sending the specimen to a centralized laboratory. Po-Hsun Huang described the liquefier as the first on-chip device of its kind. At the time of the report, however, the cell-analysis component had not yet been completed.

Why This Matters

Point-of-care testing means performing an analysis where care is delivered rather than transporting samples to a distant testing center. For asthma, a compact system could help connect treatment decisions to the inflammatory state inside a patient’s lungs. For tuberculosis and other pulmonary conditions, a contained disposable system could make sputum handling more practical in settings with limited laboratory infrastructure.

The work also shows why sample preparation deserves as much attention as the final measurement. A diagnostic device cannot produce useful results if it cannot safely and consistently transform an unruly clinical specimen into something its sensors can read. By shrinking the liquefaction step onto a chip and cutting the required sample volume, the Penn State-led team established a key building block for a more portable sputum-testing workflow.

What Comes Next

The next task is to integrate the liquefier with the planned flow-cytometry analysis component and demonstrate a complete diagnostic process. If that integration works as intended, the platform could move sputum processing and lung-cell analysis closer to clinics, nurses, and possibly patients’ homes. The research was supported by the American Asthma Foundation Scholar Award, the National Science Foundation, and NHLBI’s Division of Intramural Research.

Topics: Lab-on-a-chip · Diagnostics & precision medicine · Immunity & inflammation · Infectious diseases

Start here: Lab-on-a-chip explained