Techniques for manipulating, separating, and trapping particles and cells are highly desired in today's bioanalytical and biomedical field. The microfluidic chip-based acoustic noncontact trapping method earlier developed within the group now provides a flexible platform for performing cell-and particle-based assays in continuous flow microsystems. An acoustic standing wave is generated in etched glass channels (600 × 61 µm 2) by miniature ultrasonic transducers (550 × 550 × 200 µm 3). Particles or cells passing the transducer will be retained and levitated in the center of the channel without any contact with the channel walls. The maximum trapping force was calculated to be 430 (135 pN by measuring the drag force exerted on a single particle levitated in the standing wave. The temperature increase in the channel was characterized by fluorescence measurements using rhodamine B, and levels of moderate temperature increase were noted. Neural stem cells were acoustically trapped and shown to be viable after 15 min. Further evidence of the mild cell handling conditions was demonstrated as yeast cells were successfully cultured for 6 h in the acoustic trap while being perfused by the cell medium at a flowrate of 1 µL/min. The acoustic microchip method facilitates trapping of single cells as well as larger cell clusters. The noncontact mode of cell handling is especially important when studies on nonadherent cells are performed, e.g., stem cells, yeast cells, or blood cells, as mechanical stress and surface interaction are minimized. The demonstrated acoustic trapping of cells and particles enables cell-or particle-based bioassays to be performed in a continuous flow format.

No abstract

No abstract

Fracture testing of silicon cantilever beams (thicknesses 10–20 μm) was performed in situ in a scanning electron microscope by means of an equipment specially designed for this purpose. Beams of various sizes and orientations (〈011〉 and 〈001〉) were manufactured in Si (100) wafers by two different micromachining procedures. The beams were tested by simple bending to fracture, and a number of fundamental fracture parameters were determined from an analytical model of elastic fracture. To verify its validity, the model was utilized to evaluate an experimental E modulus, which was found to agree well with previous results. Fracture limits, fracture strains, and initiating flaw sizes were determined. The maximum fracture limit was very high; about 10 GPa. The strengths of different beams scattered from this value down to practically zero strength, with an average close to 4 GPa. The corresponding fracture strains and initiating flaw sizes were 6% and 3 nm, respectively (maximum strength), and 2% and 17 nm (average strength). Finally, a simple fractography study was performed on the fractured beams.

The COVID-19 pandemic has meant a rapid transfer of everyday activities to the online world. Information and communication technologies (ICTs) have become more embedded than ever in people's lives. This investigation addresses how this change has affected the lives of people with intellectual disabilities (ID). A two-step design was used. A rapid review was conducted on empirical studies published between January 2019 and June 2021. Search terms related to ID, ICT use and COVID-19. A qualitative international bricolage was also conducted corresponding to author nationalities. Data gathered from the review and bricolage were analysed separately using thematic analysis and relationally synthesised. Digital solutions to provide access to COVID-19 information and guidance seemed inadequate but were seldom empirically studied. Digital poverty, literacy and exclusion remain significant issues for people with ID internationally. People and their carers experienced reduced and removed service provision, loneliness and impoverished daily lives during the pandemic; amelioration of which was facilitated by digital solutions. One solution often used was videoconferencing. Prior experience of digital participation, adequate finances, connection, support and digital literacy mentoring for both people with ID and those providing services and support facilitated digital inclusion.Digital exclusion during COVID-19 was exacerbated by sociopolitical, structural, individual and support-related barriers. Although awareness of digital exclusion appears to have been raised, the extent to which this has led to action and change remains unclear. Despite digital exclusion and digital participation benefitting continuation of life, social and emotional well-being and autonomy, COVID-19 has not provided the impetus to eradicate digital poverty for people with ID. Governmental support, digital education, creativity and problem solving are required to enable List of abbreviations: AMSTAR, assessing the methodological quality of systematic reviews; ASD, autistic spectrum disorder; ICT, information and communication technologies; ID, intellectual disability; PRISMA, preferred reporting items for systematic reviews and meta-analyses; UNCRPD, united nations convention on the rights of persons with disabilities; WHO, world health organisation.

No abstract

No abstract

An acoustic microfluidic system for miniaturized fluorescence activated cell sorting (µ FACS) is presented.