Kevin Kung

We are developing a low-cost photospectrometer on camera phones for potential wide-ranging uses such as water testing and medical diagnostics in resource-constrained settings. Prototype awarded the Grand Prize in the 2013 MIT/Harvard International Development Hackathon and subsequently received support from Prof. Ramesh Raskar at MIT.

The Coriolis hematocrit centrifuge is designed for rural clinics that do not have access to electricity or to state-of-the-art centrifuges in developing countries such as India. Compared to existing low-cost and manual centrifuges in the market, our prototype is smaller, lighter, more affordable, safer to operate, and easier to locally manufacture/maintain, and does not rely on advanced machining tools. In fact, it is even portable by community health workers in rural areas that need to make… Show more

The Coriolis hematocrit centrifuge is designed for rural clinics that do not have access to electricity or to state-of-the-art centrifuges in developing countries such as India. Compared to existing low-cost and manual centrifuges in the market, our prototype is smaller, lighter, more affordable, safer to operate, and easier to locally manufacture/maintain, and does not rely on advanced machining tools. In fact, it is even portable by community health workers in rural areas that need to make village visits. Our initial target market will be anemia diagnosis, because anemia affects 3 billion and causes 30% of maternal/child deaths. Our product received customer acclaimed in rural Nigeria, and was featured as one of the "Top 50" in the 2012 James Dyson Award for international student design, as well as one of the 10 competing semi-finalists in the 2013 American Society of Mechanical Engineers IShow. We are currently exploring further user-centered iterations and initial production in India. Show less

We prototyped a low-cost shower module for use in households in urban slums whose only current access to personal hygiene are public showers, which can be unsafe at night, especially for women. Our module is designed to be manufacturable using locally available materials, and is currently slated for commercial production in collaboration with the Amusha Youth Organization and Sanergy in Nairobi, Kenya. Project awarded Team Spirit Award at the 2012 MIT IDEAS/Global Challenge Competition.

As per standard ambulance protocol, when the ambient temperature is below a certain threshold, it is necessary to keep the ambulance engine running while outside (i.e. “idling”) because of the need to keep the cabin warm using the engine-heated heating system. This tends to be expensive in terms of fuel consumption and operating costs, and can also wear down the engine. While existing idle reduction technologies exist, they are often adapted from other applications such as fire apparatuses or… Show more

As per standard ambulance protocol, when the ambient temperature is below a certain threshold, it is necessary to keep the ambulance engine running while outside (i.e. “idling”) because of the need to keep the cabin warm using the engine-heated heating system. This tends to be expensive in terms of fuel consumption and operating costs, and can also wear down the engine. While existing idle reduction technologies exist, they are often adapted from other applications such as fire apparatuses or police vehicles, which can have somewhat different functional requirements than ambulances. Such systems tend to be expensive and/or require intensive battery storage and monitoring. By studying the non-emergent operations of a collegiate ambulance service (MIT EMS), we realized that in this particular case, most idling intervals are short (less than 30 minutes) relative to the timescale of heat loss from the patient compartment, and that the need for idling is mainly driven by temperature management rather than power management. This has enabled us to propose a simple, automated system design that constantly monitors the temperature in the patient compartment, and only starts the vehicle engine and heating system temporarily when the temperature falls below a preset threshold in the cabin. The simplest embodiment of this design, consisting of a remote starter operating in cold start mode and a modified temperature sensor, costs approximately one-sixth (~$750) compared to currently commercially available systems to install. A preliminary prototype system was installed on the MIT EMS ambulance (gas engine), and from the initial testing data, we estimate that our system can reduce the vehicle’s idling fuel consumption and engine run time by about 85%. Future work includes studying the system’s compatibility with diesel engine, adding dynamic control for engine run time and heater setting, and exploring the needs and requirements of other ambulance services. Show less

Advised an S.B. thesis (Kathryn Wopat) on the experimental visualization of fluid mixing for the application of volatile gas combustion in a small-scale biomass torrefaction system.

This MIT student project report, carried out in collaboration with NovaGen Power Solutions, describes the technical assessment and comparison between gasification and anaerobic digestion of organic food waste for power generation in urban Nigeria.

Advised an S.B. thesis (Jonathan Rea) on the kinetic modeling and experimental measurement of biogas production from chicken litter.

We aim to better understand the proliferative and migratory behaviors of different epithelial lineages in the murine intestinal crypt, and apply this to an APC-deficient cancer model to gain insight into the dynamics of progression of early-stage adenomas. While intestinal cell behavior has been widely studied and modeled, most of these studies are based on the so-far ill-quantified “clonal conveyor belt” model of cell migration, which assumes that cells in the renewing portion of the tissue… Show more

We aim to better understand the proliferative and migratory behaviors of different epithelial lineages in the murine intestinal crypt, and apply this to an APC-deficient cancer model to gain insight into the dynamics of progression of early-stage adenomas. While intestinal cell behavior has been widely studied and modeled, most of these studies are based on the so-far ill-quantified “clonal conveyor belt” model of cell migration, which assumes that cells in the renewing portion of the tissue, regardless of lineage, behave similarly in migratory behaviors. Using single-molecule fluorescent in situ hybridization (smFISH) against lineage markers in combination with EdU pulse-chase labeling and/or lineage tracing as measures for cell proliferation and migration, we quantified the lineage-dependent cell behaviors in greater detail. If there are any significant phenomenological differences between the lineages, then we also hope to better understand the molecular underpinning of such differences by comparing expression patterns in the different lineages. Finally, we applied the same approach to examine lineage-dependent cell migration and proliferation in an early-stage adenoma model, whose cell behaviors are currently poorly understood beyond the well-studied putative LGR5-expressing “cancer stem cells”. Show less

In 2008, the Engeye foundation, a group responsible for health care in the rural community of Ddegeya Uganda, contacted Engineers Without Borders-MIT looking to form a partnership through which solutions to the dire water resource and energy supply problems experienced by the clinic and its surrounding community could be found. Our project focused primarily on the water aspect after identifying this as the most urgent issue needing to be addressed within the community. The primary objective of… Show more

In 2008, the Engeye foundation, a group responsible for health care in the rural community of Ddegeya Uganda, contacted Engineers Without Borders-MIT looking to form a partnership through which solutions to the dire water resource and energy supply problems experienced by the clinic and its surrounding community could be found. Our project focused primarily on the water aspect after identifying this as the most urgent issue needing to be addressed within the community. The primary objective of the trip was to test the suitability of prototype technologies under consideration for implementation through introductory community involvement and evaluation, which would enable the community to participate in the construction and testing of these prototypes built from locally sourced materials. We successfully built and distributed two Biosand filters and two solar cookers, from which we are currently receiving information on their performance. In conjunction to this, we also took apart a number of non functional India Mark 2 and 3 hand pumps to gauge whether repairing these or installing new ones in strategic locations could be a solution to the accessibility problem. Throughout our trip we also continued to document the various water sources available to the community (open ponds, boreholes, and rainwater)—as well as to monitor the water quality—gin an attempt quantify the seasonal variation in both water quality and quantity. Show less

Both MCF-10A and MDA-MB-231 are well-established mammary epithelial cell lines at different stages of oncogenesis. While MCF-10A is an immortalized cell line derived from a benign fibrocyst, its proliferation depends on both anchorage and biochemical signaling. In contrast, MDA-MB-231 was isolated from a triple-negative metastatic breast carcinoma with a poor prognosis, and has acquired high levels of pro-survival signal. We have cultured both cell lines as a 2D adherent monolayer and… Show more

Both MCF-10A and MDA-MB-231 are well-established mammary epithelial cell lines at different stages of oncogenesis. While MCF-10A is an immortalized cell line derived from a benign fibrocyst, its proliferation depends on both anchorage and biochemical signaling. In contrast, MDA-MB-231 was isolated from a triple-negative metastatic breast carcinoma with a poor prognosis, and has acquired high levels of pro-survival signal. We have cultured both cell lines as a 2D adherent monolayer and qualitatively characterized some of their properties in vitro. In general, we found that MCF-10A cells tend to grow in clusters, independent of the original seeding density. While in clusters, they tend to assume a condensed morphology, and while in isolation, an elongated morphology. On the other hand, MDA-MB-231 cells are generally spindle-shaped, and tend to be found in isolation. A significant fraction of MDA-MB-231 cells are also rounded up, suggesting either frequent apoptosis and/or cell division. Somewhat surprisingly, MDA-MB-231 cells grow at a noticeably slower rate than MCF-10A cells: when seeded at the same density, the former required an extra 1-2 d to reach confluency. Furthermore, we have also begun to characterize the location and number of cMyc and E2F1 mRNA transcripts using fluorescent in-situ hybridization (FISH). In the future, selected mRNA transcripts in these two cell lines are poised for more quantitative FISH analysis and comparison. Show less

3T3 fibroblasts cultured on microgrooved polydimethylsiloxane (PDMS) surfaces of two different widths (25 μm and 55 μm) were individually tracked using confocal microscopy with a novel live-cell staining technique over several hours without noticeable cytotoxic effects. By quantifying the cell morphology, orientation, and migration over time, we identified the timescale (about 2-4 h after seeding) over which cell behaviors transitioned from isotropy to anisotropy, where the preference is in the… Show more

3T3 fibroblasts cultured on microgrooved polydimethylsiloxane (PDMS) surfaces of two different widths (25 μm and 55 μm) were individually tracked using confocal microscopy with a novel live-cell staining technique over several hours without noticeable cytotoxic effects. By quantifying the cell morphology, orientation, and migration over time, we identified the timescale (about 2-4 h after seeding) over which cell behaviors transitioned from isotropy to anisotropy, where the preference is in the direction parallel to the pattern. The development of anisotropy occurred more rapidly and distinctly when a narrower ridge width was used, suggesting that it is the ridge width that imposed a physical barrier on the cells' morphology and motility. Furthermore, while we found a weak but statistically significant correlation between cell orientation and morphology on the single-cell level, there is a lack of correlation on the same level between cell orientation and migratory direction. This suggests that while morphology and migration are affected anisotropically by topographical patterns in a similar way, the underlying processes giving rise to the anisotropy is slightly different in the two cases. Show less

Bacterial chemotaxis is a well-studied phenomenon; however, there are still debates and seemingly contradictory datasets regarding the kinetics of the bacterial flagellar motor switching. As a result, more and more elaborate models—including those with multiple indistinguishable motor states—have been proposed in an attempt to rationalize the motor switching data. Using the tethered cell assay, we collected a large amount of switching data from two Escherichia coli strains—one wild-type and one… Show more

Bacterial chemotaxis is a well-studied phenomenon; however, there are still debates and seemingly contradictory datasets regarding the kinetics of the bacterial flagellar motor switching. As a result, more and more elaborate models—including those with multiple indistinguishable motor states—have been proposed in an attempt to rationalize the motor switching data. Using the tethered cell assay, we collected a large amount of switching data from two Escherichia coli strains—one wild-type and one mutant in chemotactic pathway serving as a control—and discovered, in agreement with previous studies, two unusual fea- tures in the interswitch interval distributions: a short-term peak and a long-term heavy tail. In order to account for these features, we rigorously considered how physical and in- strumental limitations in data collection and processing could affect the parsing of CCW and CW events. We showed that the short-term peak can be sufficiently explained by these physical limitations in lieu of the previous elaborate biological models. In light of this, we proposed the intermediate-state model, which is able to accommodate both the physical limitations and various alternate motor switching mechanisms that have been suggested. Furthermore, we found that variability in motor kinetics on both the single-cell and the population levels, at least qualitatively, gives rise to long-term power-law behavior in inter- switch interval lengths, akin to the broad-tailed distribution observed in our experimental data. If bacterial movement indeed follows some power-law behavior, then this has impli- cations in that a power-law-based random walk has been shown to optimize an organism’s foraging strategy. Show less

Optimizing the tissue-implant adhesion is still major challenge in developing biomedical devices for hip or knee replacement. In this project, we sintered bioactive glass onto titanium surface at different conditions (temperature, length of time). We studied the resultant surface texture, and determined its suitability for use in tissue-implant interfaces.

In gravitational wave experiments, the ability to detect chirps—oscillating signals whose frequency varies with time—from noisy background is of critical importance. Conventional techniques such as the Fourier transform (FT) have been modified to gauge how the frequency content of a signal varies with time. However, a newer approach has been proposed: the Hilbert-Huang transform (HHT), an empirical process that explores a very different set of assumptions from that of FT. We first outlined how… Show more

In gravitational wave experiments, the ability to detect chirps—oscillating signals whose frequency varies with time—from noisy background is of critical importance. Conventional techniques such as the Fourier transform (FT) have been modified to gauge how the frequency content of a signal varies with time. However, a newer approach has been proposed: the Hilbert-Huang transform (HHT), an empirical process that explores a very different set of assumptions from that of FT. We first outlined how FT can be modified to detect chirp signals, then examined the properties of the HHT and how it could be used to achieve the same end. Finally, we devised a quantitative method to compare the chirp-detection performance of the modified short-time FT (STFT) and the HHT, and found that our implementation of HHT, at various noise-to-chirp-amplitude ratios, consistently fares worse than our implementation of STFT at rejecting the null hypothesis that a signal has only Gaussian noise. Various improvements on HHT are needed before it can compete with STFT in analyzing chirp signals. Show less

Inspired by experiments confirming the existence of some individuals with higher mutation rates (mutators) in a population, and previous theoretical works, we develop a model to describe the dynamics of mutators in an asexual population. We begin by modeling deleterious mutations only, and show that in this scenario mutators are outcompeted by non-mutators. Then, we extend our model to include beneficial mutations, by examining circumstances in which mutators have a strong advantage over non-… Show more

Inspired by experiments confirming the existence of some individuals with higher mutation rates (mutators) in a population, and previous theoretical works, we develop a model to describe the dynamics of mutators in an asexual population. We begin by modeling deleterious mutations only, and show that in this scenario mutators are outcompeted by non-mutators. Then, we extend our model to include beneficial mutations, by examining circumstances in which mutators have a strong advantage over non- mutators. We show that whether or not mutators take over the population depends primarily on the effect of beneficial mutations relative to two factors: (1) the effects of deleterious mutations, and (2) the rate of deleterious mutations. Under different regimes, factors (1) and (2) act in opposite or in parallel to each other in dictating the probability that mutators establish themselves. Show less

I researched, designed, built, and tested a magnetic susceptometer that can detect when a sample transitions into superconduction in neutron scattering experiments.